<PAGE>
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OMB APPROVAL
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OMB Number: 3235-0006
Expires: FEBRUARY 28, 1994
Estimated average burden
UNITED STATES hours per response . . . 24.60
SECURITIES AND EXCHANGE COMMISSION ------------------------------
Washington, D.C. 20549 SEC USE ONLY
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INFORMATION REQUIRED OF INSTITUTIONAL INVESTMENT MANAGERS PURSUANT
TO SECTION 13(f) OF THE SECURITIES EXCHANGE ACT OF 1934 AND RULES THEREUNDER
Report for the Calendar Year or Quarter Ended: SEPTEMBER 30, 1999.
------------------
- --------------------------------------------------------------------------------
(Please read instructions before preparing form.)
- --------------------------------------------------------------------------------
If amended report check here: [_]
- --------------------------------------------------------------------------------
Name of Institutional Investment Manager
125 HIGH STREET, 29TH FLOOR, BOSTON, MA 02110
- --------------------------------------------------------------------------------
Business Address (Street) (City) (State) (Zip)
C. H. RITT III, 617-342-3200, VICE PRESIDENT
- --------------------------------------------------------------------------------
Name, Phone No., and Title of Person Duly Authorized to submit this Report.
- ---------------------------------- ATTENTION -----------------------------------
Intentional misstatement or omissions of facts
constitute Federal Criminal Violations.
See 18 U.S.C. 101 and 15 U.S.C. 78ff(a).
- --------------------------------------------------------------------------------
The institutional investment manager submitting this form and its
attachments and the person by whom it is signed represent hereby that all
information contained therein is true, correct and complete. It is understood
that all required items, statements and schedules are considered integral parts
of this Form and that the submission of any amendment represents that all
unamended items, statements and schedules remain true, correct and complete as
previously submitted.
Pursuant to the requirements of Securities Exchange Act of 1934, the
undersigned institutional investment manager has caused this report to be signed
on its behalf in the city of BOSTON and State of MA on the 9th day of OCTOBER,
1999.
ESSEX INVESTMENT MANAGEMENT COMPANY, LLC
-------------------------------------------
(Name of Institutional Investment Manager)
/s/ Illegible Signature
-------------------------------------------
(Manual Signature of Person Duly Authorized
to Submit This Report)
Name and 13F file numbers of ALL Institutional Investment Managers with respect
to which this schedule is filed (other than the one filing this report): (List
in alphabetical order).
13F File Number will be assigned to Institutional Investment Managers after they
file their first report.
Name: 13F File No:
- ---------------------------------------- -----------------
1. AFFILIATED MANAGERS GROUP, INC. PENDING
- ---------------------------------------- -----------------
2.
- ---------------------------------------- -----------------
3.
- ---------------------------------------- -----------------
4.
- ---------------------------------------- -----------------
5.
- ---------------------------------------- -----------------
6.
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7.
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8.
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9.
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10.
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SEC 1685 (5/91)
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 1
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
AGCO CORP COMMON 001084102 130 10000 10000 0 0 10000
AT&T CORP COMMON 001957109 229 5267 5267 0 0 5267
ABACUS DIRECT CORP COMMON 002553105 1030 8450 8450 6750 0 1700
ABBOTT LABS COMMON 002824100 2591 70615 70615 28715 0 41900
ABERCROMBIE & FITCH CO COMMON 002896207 2738 80380 80380 53640 0 26740
ACCREDO HEALTH INC COMMON 00437V104 9060 287620 287620 222045 0 65575
ACCRUE SOFTWARE INC COMMON 00437W102 555 24655 24655 16435 0 8220
ADVANCE PARADIGM INC COMMON 007491103 42911 783755 783755 660395 0 123360
ADVANCED MARKETING SVCS COMMON 00753T105 228 11550 11550 11550 0 0
ADVANTAGE LEARNING SYSTE COMMON 00757K100 8821 473600 473600 411700 0 61900
ADVENT SOFTWARE INC COMMON 007974108 616 9900 9900 9900 0 0
AFFYMETRIX INC COMMON 00826T108 315 3200 3200 2700 0 500
AGILE SOFTWARE CORP DEL COMMON 00846X105 1843 28790 28790 21920 0 6870
AIR EXPRESS INTL CORP COMMON 009104100 1159 51100 51100 43000 0 8100
AIR PRODS & CHEMS INC COMMON 009158106 211 7220 7220 5500 0 1720
AIRGATE PCS INC COMMON 009367103 16803 675500 675500 496655 0 178845
ALBANY MOLECULAR RESH IN COMMON 012423109 3862 153710 153710 145635 0 8075
ALCOA INC COMMON 013817101 236 3800 3800 3800 0 0
ALLAIRE CORP COMMON 016714107 80515 1437767 1437767 1195570 0 242197
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 174808261 4153329 4153329 3350260 803069
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 2
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
ALLEGIANCE TELECOM INC COMMON 01747T102 35604 676555 676555 534085 0 142470
ALLIANCE SEMICONDUCTOR C COMMON 01877H100 575 54150 54150 34500 0 19650
ALLIED CAP CORP NEW COMMON 01903Q108 504 22460 22460 22460 0 0
ALLIEDSIGNAL INC COMMON 019512102 480 8000 8000 8000 0 0
ALLTEL CORP COMMON 020039103 1817 25813 25813 14340 0 11473
ALPHA INDS INC COMMON 020753109 336 5950 5950 5950 0 0
ALPHARMA INC COMMON 020813101 950 26900 26900 26900 0 0
ALPHA 1 BIOMEDICALS INC COMMON 020910105 3 112000 112000 0 0 112000
AMAZON COM INC COMMON 023135106 154790 1936391 1936391 1426591 0 509800
AMERICA ONLINE INC DEL COMMON 02364J104 76948 739438 739438 592270 0 147168
AMERICAN BIOGENETIC SCIE COMMON 024611105 3 10000 10000 0 0 10000
AMERICAN EAGLE OUTFITTER COMMON 02553E106 1228 25350 25350 24800 0 550
AMERICAN EXPRESS CO COMMON 025816109 9626 71305 71305 50425 0 20880
AMERICAN GENERAL CORP COMMON 026351106 727 11488 11488 0 0 11488
AMERICAN HOME PRODS CORP COMMON 026609107 787 18955 18955 0 0 18955
AMERICAN INTL GROUP INC COMMON 026874107 33691 387532 387532 291011 0 96521
AMERICAN MGMT SYS INC COMMON 027352103 272 10600 10600 10600 0 0
AMERICREDIT CORP COMMON 03060R101 648 43400 43400 43400 0 0
AMES DEPT STORES INC COMMON 030789507 647 20300 20300 20300 0 0
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 322550168 4252688 4252688 3118232 1134456
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 3
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
AMERITECH CORP NEW COMMON 030954101 300 4500 4500 0 0 4500
AMGEN INC COMMON 031162100 26766 328420 328420 265645 0 62775
AMKOR TECHNOLOGY INC COMMON 031652100 1543 95700 95700 61400 0 34300
ANADARKO PETE CORP COMMON 032511107 52601 1721095 1721095 1500565 0 220530
ANGLOGOLD LTD COMMON 035128206 9494 302000 302000 269000 0 33000
ANHEUSER BUSCH COS INC COMMON 035229103 16966 242155 242155 172600 0 69555
ANNTAYLOR STORES CORP COMMON 036115103 531 13000 13000 13000 0 0
AON CORP COMMON 037389103 665 22500 22500 0 0 22500
APACHE CORP COMMON 037411105 19020 440396 440396 368321 0 72075
APPLE COMPUTER INC COMMON 037833100 733 11575 11575 9600 0 1975
APPLEBEES INTL INC COMMON 037899101 1324 39300 39300 39300 0 0
APPLIED MATLS INC COMMON 038222105 6837 88000 88000 69200 0 18800
APPLIED MICRO CIRCUITS C COMMON 03822W109 17447 306080 306080 239815 0 66265
ARDENT SOFTWARE INC COMMON 039794102 1209 44900 44900 44900 0 0
ARIBA INC COMMON 04033V104 60687 419980 419980 345875 0 74105
ARMOR HOLDINGS INC COMMON 042260109 254 23400 23400 23400 0 0
ARROW ELECTRS INC COMMON 042735100 696 39500 39500 39500 0 0
ART TECHNOLOGY GROUP INC COMMON 04289L107 22515 591520 591520 467515 0 124005
ARTISAN COMPONENTS INC COMMON 042923102 1210 140300 140300 90800 0 49500
---------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 2411745115 4887446 4887446 4029236 858210
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 4
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
ARTESYN TECHNOLOGIES INC COMMON 043127109 643 33900 33900 33900 0 0
ARTHROCARE CORP COMMON 043136100 1082 19800 19800 19800 0 0
ASARCO INC COMMON 043413103 589 21800 21800 21800 0 0
ASK JEEVES INC COMMON 045174109 290 8400 8400 6800 0 1600
ASPECT DEV INC COMMON 045234101 1753 69260 69260 63260 0 6000
AT HOME CORP COMMON 045919107 374 9032 9032 0 0 9032
ASYST TECHNOLOGY CORP COMMON 04648X107 1940 58800 58800 37700 0 21100
ATLANTIC RICHFIELD CO COMMON 048825103 479 5400 5400 5400 0 0
ATMEL CORP COMMON 049513104 10656 315150 315150 250650 0 64500
AURORA BIOSCIENCES CORP COMMON 051920106 1648 120950 120950 120950 0 0
AUTOMATIC DATA PROCESSIN COMMON 053015103 336 7529 7529 0 0 7529
AVANT IMMUNOTHERAPEUTICS COMMON 053491106 64 30000 30000 0 0 30000
AXENT TECHNOLOGIES INC COMMON 05459C108 381 29478 29478 0 0 29478
BISYS GROUP INC COMMON 055472104 639 13620 13620 13620 0 0
BJ SVCS CO COMMON 055482103 39683 1247400 1247400 1045350 0 202050
BP AMOCO P L C COMMON 055622104 2360 21296 21296 2024 0 19272
BAKER HUGHES INC COMMON 057224107 19279 664805 664805 560050 0 104755
BARRICK GOLD CORP COMMON 067901108 8791 404200 404200 357900 0 46300
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 91393361 3091337 3091337 2546604 544733
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 5
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
BE INC COMMON 073309106 918 130000 130000 130000 0 0
BEA SYS INC COMMON 073325102 22528 637975 637975 474150 0 163825
BEBE STORES INC COMMON 075571109 422 17500 17500 17500 0 0
BELL ATLANTIC CORP COMMON 077853109 788 11702 11702 700 0 11002
BELLSOUTH CORP COMMON 079860102 228 5064 5064 2292 0 2772
BENIHANA INC CL A 082047200 419 25600 25600 25600 0 0
BERRY PETE CO CL A 085789105 136 10000 10000 10000 0 0
BEST BUY INC COMMON 086516101 387 6245 6245 4020 0 2225
BIOCHEM PHARMA INC COMMON 09058T108 1633 68200 68200 57800 0 10400
BIOGEN INC COMMON 090597105 20327 257920 257920 229920 0 28000
BLUESTONE SOFTWARE INC SER C PFD PRIV 095991105 4462 241173 241173 136568 0 104605
BLUESTONE SOFTWARE INC COMMON 09623P102 1399 60480 60480 39600 0 20880
BRAUNS FASHIONS CORP COMMON 105658108 862 47400 47400 47400 0 0
BRIGHT HORIZON FAMILY SO COMMON 109195107 1297 83018 83018 43569 0 39449
BRISTOL MYERS SQUIBB CO COMMON 110122108 704 10424 10424 3850 0 6574
BROADBASE SOFTWARE COMMON 11130R100 515 32337 32337 23592 0 8745
BROADCOM CORP CL A 111320107 62196 570610 570610 479700 0 90910
BROCADE COMMUNICATIONS S COMMON 111621108 63861 304100 304100 263220 0 40880
BROWN TOM INC COM NEW 115660201 211 14300 14300 14300 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 184097679 2536287 2536287 2004116 532171
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 6
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
BROWN SHOE INC NEW COMMON 115736100 452 24700 24700 24700 0 0
BUCA INC COMMON 117769109 309 23785 23785 13265 0 10520
BUFFETS INC COMMON 119882108 1163 100000 100000 100000 0 0
BURLINGTON RES INC COMMON 122014103 33606 914440 914440 773745 0 140695
BURNHAM PAC PPTYS INC COMMON 12232C108 250 23625 23625 775 0 22850
BURR BROWN CORP COMMON 122574106 498 12600 12600 12600 0 0
CBT GROUP PUB LTD DEPOSITORY RECEI 124853300 24681 1002280 1002280 942690 0 59590
CBS CORP COMMON 12490K107 5627 121665 121665 106875 0 14790
CD RADIO INC COMMON 125127100 638 25000 25000 25000 0 0
CEC ENTMT INC COMMON 125137109 1966 54800 54800 54800 0 0
CMGI INC COMMON 125750109 137638 1342809 1342809 1094005 0 248804
CNET INC COMMON 125945105 25866 461900 461900 411200 0 50700
CSK AUTO CORP COMMON 125965103 232 10650 10650 10650 0 0
CTS CORP COMMON 126501105 1415 24600 24600 24600 0 0
CVS CORP COMMON 126650100 26853 657956 657956 561451 0 96505
C PORT SERIES C COMMON 126993104 1000 366300 366300 0 0 366300
CAREER EDUCATION CORP COMMON 141665109 252 8700 8700 1200 0 7500
CAREMARK RX INC COMMON 141705103 575 100000 100000 100000 0 0
CELESTIAL SEASONINGS INC COMMON 151016102 8398 436260 436260 323675 0 112585
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 272868974 5737720 5737720 4586731 1150989
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 7
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
CENDANT CORP COMMON 151313103 15304 862200 862200 626360 0 235840
CENTURYTEL INC COMMON 156700106 2810 69176 69176 44307 0 24869
CERETEK LLC COMMON 156990103 800 18000 18000 18000 0 0
CHARMING SHOPPES INC COMMON 161133103 151 29500 29500 29500 0 0
CHECKFREE HLDGS CORP COMMON 162816102 1952 47475 47475 3000 0 44475
CHEMDEX CORP COMMON 163595101 234 7580 7580 7580 0 0
CHEVRON CORPORATION COMMON 166751107 714 8043 8043 2190 0 5853
CHIREX INC COMMON 170038103 671 26000 26000 26000 0 0
CHUBB CORP COMMON 171232101 293 5900 5900 0 0 5900
CIENA CORP COMMON 171779101 28416 778533 778533 607409 0 171124
CINAR CORP COMMON 171905300 1960 64800 64800 48400 0 16400
CIRCLE INTL GROUP INC COMMON 172574105 245 12000 12000 12000 0 0
CIRCUIT CITY STORE INC COMMON 172737108 13232 313640 313640 259795 0 53845
CIRRUS LOGIC CORP COMMON 172755100 616 56000 56000 56000 0 0
CISCO SYS INC COMMON 17275R102 79500 1159524 1159524 975923 0 183601
CITIGROUP INC COMMON 172967101 615 13985 13985 3025 0 10960
CLEAR CHANNEL COMMUNICAT COMMON 184502102 17033 213250 213250 184130 0 29120
COBALT NETWORKS, INC COMMON 190990101 750 202702 202702 0 0 202702
COCA COLA CO COMMON 191216100 1077 22317 22317 13930 0 8387
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 167162346 3923325 3923325 2928249 995076
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 8
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
COLE KENNETH PRODTNS INC COMMON 193294105 482 12900 12900 12900 0 0
COLGATE PALMOLIVE CO COMMON 194162103 739 16160 16160 160 0 16000
COMDIAL CORP COMMON 200332302 97 13400 13400 13400 0 0
COMMSCOPE INC COMMON 203372107 23867 734355 734355 605500 0 128855
COMVERSE TECHNOLOGY INC COMMON 205862402 58984 625405 625405 435265 0 190140
CONCENTRIC NETWORK CORP COMMON 20589R107 2783 137000 137000 126200 0 10800
CONCORD COMMUNICATIONS I COMMON 206186108 826 20775 20775 18500 0 2275
CONCORD EFS INC COMMON 206197105 467 22650 22650 14700 0 7950
CONEXANT SYSTEMS INC COMMON 207142100 7444 102450 102450 99100 0 3350
CONOCO INC COMMON 208251306 466 16800 16800 16800 0 0
CONSOLIDATED GRAPHICS IN COMMON 209341106 468 11100 11100 11100 0 0
COOPER CAMERON CORP COMMON 216640102 236 6260 6260 6260 0 0
COPPER MTN NETWORKS INC COMMON 217510106 1753 20000 20000 0 0 20000
COREL CORPORATION COMMON 21868Q109 1092 147500 147500 147500 0 0
CORNING INC COMMON 219350105 249 3635 3635 2800 0 835
CORPORATE EXECUTIVE BRD COMMON 21988R102 705 17310 17310 11020 0 6290
COSTCO WHSL CORP NEW COMMON 22160K105 8179 113593 113593 71355 0 42238
COSTAR GROUP INC COMMON 22160N109 7043 295010 295010 235190 0 59820
COVAD COMMUNICATIONS GRO COMMON 222814204 89326 2049061 2049061 1605984 0 443077
---------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 2065958500 4397451 4397451 3449034 948417
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 9
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
CREATIVE BIOMOLECULES IN COMMON 225270107 626 166800 166800 140900 0 25900
CREDENCE SYS CORP COMMON 225302108 938 20900 20900 20900 0 0
CREO PRODS INC COMMON 225606102 693 28200 28200 28200 0 0
CRITICAL PATH INC COMMON 22674V100 4614 114375 114375 85425 0 28950
CROSSROADS SYSTEMS SER E COMMON 227990108 2250 225000 225000 0 0 225000
CURAGEN CORP COMMON 23126R101 172 13000 13000 13000 0 0
CYBERGOLD INC COMMON 23246N105 540 54675 54675 34320 0 20355
CYPRESS SEMICONDUCTOR CO COMMON 232806109 36967 1719375 1719375 1378575 0 340800
CYTYC CORP COMMON 232946103 1517 39200 39200 39200 0 0
DAYTON HUDSON CORP COMMON 239753106 210 3490 3490 3490 0 0
DELIA*S INC COMMON 246885107 819 130350 130350 97065 0 33285
DEVON ENERGY CORP NEW COMMON 25179M103 9640 232634 232634 184045 0 48589
DIAMOND OFFSHORE DRILLIN COMMON 25271C102 991 29685 29685 29685 0 0
DIAMOND TECHNOLOGY PARTN CL A 252762109 5883 131100 131100 113700 0 17400
DIGEX INC DEL CL A 253756100 1089 45975 45975 39180 0 6795
DIGITAL MICROWAVE CORP COMMON 253859102 2072 132100 132100 88000 0 44100
DIGITAL INSIGHT CORP COMMON 25385P106 749 49920 49920 40335 0 9585
DIGITAL RIV INC COMMON 25388B104 4516 207655 207655 166105 0 41550
DOLLAR TREE STORES INC COMMON 256747106 5690 142470 142470 142470 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 81486891 3497204 3497204 2650695 846509
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 10
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
DOUBLECLICK INC COMMON 258609304 2903 24372 24372 5300 0 19072
DRUGSTORE COM INC COMMON 262241102 28678 791125 791125 653870 0 137255
DU PONT E I DE NEMOURS & COMMON 263534109 539 8912 8912 1550 0 7362
E M C CORP MASS COMMON 268648102 68639 961670 961670 856355 0 105315
ENSCO INTL INC COMMON 26874Q100 7117 394000 394000 338200 0 55800
E PIPHANY INC COMMON 26881V100 27393 561915 561915 437780 0 124135
ESAT TELECOM GROUP PLC COMMON 26883Y102 566 14230 14230 3325 0 10905
E-TEK DYNAMICS INC COMMON 269240107 4074 75100 75100 40300 0 34800
EBAY INC COMMON 278642103 400 2836 2836 2436 0 400
ECLIPSE SURGICAL TECHNOL COMMON 278849104 2749 166600 166600 118900 0 47700
EGAIN COMMUNICATIONS COMMON 28225C103 496 26800 26800 20500 0 6300
ELECTRO SCIENTIFIC INDS COMMON 285229100 698 13100 13100 13100 0 0
ELECTROGLAS INC COMMON 285324109 367 15700 15700 15700 0 0
ELECTRONIC ARTS INC COMMON 285512109 347 4800 4800 4800 0 0
EMMIS COMMUNICATIONS COR COMMON 291525103 277 4200 4200 4200 0 0
EMULEX CORP COMMON 292475209 5672 66050 66050 16400 0 49650
EMUSIC COM INC COMMON 292476108 5380 361650 361650 308000 0 53650
ENDOSONICS CORP COMMON 29264K105 1423 167450 167450 163850 0 3600
ENERGIS PLC ADR COMMON 29266H100 2583 22080 22080 12375 0 9705
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 161059827 3712540 3712540 3033041 679499
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 11
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
ENGAGE TECHNOLOGIES INC COMMON 292827102 9672 256650 256650 172775 0 83875
ENRON CORP COMMON 293561106 625 15222 15222 2400 0 12822
ENTERCOM COMMUNICATIONS COMMON 293639100 1076 29900 29900 16700 0 13200
ENZON INC COMMON 293904108 3457 113350 113350 95350 0 18000
EQUANT N V COMMON 294409107 22138 272050 272050 201200 0 70850
EQUITY OFFICE PROPERTIES COMMON 294741103 344 14777 14777 5610 0 9167
ESSEX ENERGY FUND LP COMMON 296996101 7173 6500 6500 6500 0 0
ETOYS INC COMMON 297862104 2010 30200 30200 30200 0 0
EVEREST REINS HLDGS INC COMMON 299808105 229 9600 9600 4500 0 5100
EVERGREEN RES INC COMMON 299900308 361 15000 15000 15000 0 0
EXCEL SWITCHING CORP COMMON 30067V108 1123 31300 31300 30300 0 1000
EXCHANGE APPLICATIONS COMMON 300867108 355 12200 12200 8700 0 3500
EXODUS COMMUNICATIONS IN COMMON 302088109 34153 473935 473935 388070 0 85865
EXPEDITORS INTL WASH INC COMMON 302130109 12805 399000 399000 337250 0 61750
EXPRESS SCRIPTS INC COMMON 302182100 28311 361805 361805 293715 0 68090
EXTREME NETWORKS INC COMMON 30226D106 57784 912680 912680 724640 0 188040
EXXON CORP COMMON 302290101 2117 27849 27849 15334 0 12515
FVC COM INC COMMON 30266P100 1498 106500 106500 84600 0 21900
F Y I INC COMMON 302712104 276 8200 8200 8200 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 187237688 3119301 3119301 3451019 668282
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 12
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
FAIRCHILD SEMICONDUCTOR COMMON 303726103 15949 671525 671525 494150 0 177375
ESSEX HIGH TECH (USA) LP COMMON 304991102 6462 1000 1000 1000 0 0
FDX CORP COMMON 31304N107 859 22100 22100 14300 0 7800
ESSEX HIGH TECH FUND LP COMMON 313999104 1267 180 180 0 0 180
F5 NETWORKS INC COMMON 315616102 1360 20000 20000 20000 0 0
FILENET CORP COMMON 316869106 1978 185100 185100 185100 0 0
ESSEX PERFORMANCE FUND COMMON 330995101 2530 110053 110053 0 0 110053
FIRST UN CORP COMMON 337358105 1597 44830 44830 44830 0 0
FIRST YRS INC COMMON 337610109 164 16000 16000 16000 0 0
FLEXPORT EMRGING GROWTH COMMON 339994105 1250 390000 390000 0 0 390000
FLEXPORT LARGE CAP COMMON 339996100 1613 650000 650000 0 0 650000
FOODMAKER INC NEW COMMON 344839204 444 17800 17800 17800 0 0
FOREST LABS INC COMMON 345838106 14175 336505 336505 336505 0 0
FOREST OIL CORP COMMON 346091606 447 26200 26200 26200 0 0
FOUNDRY NETWORKS INC COMMON 35063R100 12219 96979 96979 74019 0 22960
FOX ENTMT GROUP INC COMMON 35138T107 1354 64300 64300 62900 0 1400
FRANCE TELECOM COMMON 35177Q105 331 3800 3800 2000 0 1800
FREESHOP COM INC COMMON 356873109 7866 684000 684000 530035 0 153965
FRONTIER CORPORATION COMMON 35906P105 217 4000 4000 0 0 4000
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 72057987 3346372 3346372 18224839 1521533
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 13
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
GTE CORP COMMON 362320103 1296 16862 16862 13625 0 3237
GANNETT INC COMMON 364730101 1038 15000 15000 15000 0 0
GARDEN COM INC COMMON 365199108 1491 79000 79000 63900 0 15100
GEERLINGS & WADE INC COMMON 368473104 106 12000 12000 0 0 12000
GENENTECH INC COMMON 368710406 21358 145975 145975 116000 0 29975
GENERAL ELEC CO COMMON 369604103 11146 94007 94007 67826 0 26181
GENERAL INSTR CORP DEL COMMON 370120107 10270 213950 213950 186250 0 27700
GENERAL SEMICONDUCTOR IN COMMON 370787103 258 25000 25000 25000 0 0
GENESYS TELECOMMUNICATIO COMMON 371931106 991 21700 21700 21700 0 0
GENOME THERAPEUTICS CORP COMMON 372430108 42 10400 10400 10400 0 0
GENZYME CORP GENL DIV COMMON 372917104 4007 88931 88931 72931 0 16000
GETTY IMAGES INC COMMON 374276103 6190 256600 256600 176200 0 80400
GILEAD SCIENCES INC COMMON 375558103 19273 300265 300265 255675 0 44590
GILLETTE CO COMMON 375766102 344 10140 10140 840 0 9300
GLENBOROUGH RLTY TR INC COMMON 37803P105 244 14800 14800 2300 0 12500
GLOBAL INDS LTD COMMON 379336100 87 10700 10700 7400 0 3300
GLOBAL MARINE INC COMMON 379352404 2578 156855 156855 154005 0 2850
GLOBAL TELESYSTEMS GROUP COMMON 37936U104 40080 2032605 2032605 1690335 0 342270
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 121781280 3552033 3552033 2900220 651813
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 14
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
GLOBESPAN INC COMMON 379571102 49672 786885 786885 604265 0 182620
GOLDMAN SACHS GROUP INC COMMON 38141G104 369 6055 6055 1160 0 4895
GOLF TR AMER INC COMMON 38168B103 531 26880 26880 18350 0 8530
GOTO COM INC COMMON 38348T107 957 18365 18365 12525 0 5840
DEJA.COM INC SER D PREFFERRED 383990108 1000 277008 277008 0 0 277008
GRANITE BROADCASTING COR COMMON 387241102 223 20000 20000 20000 0 0
GREAT PLAINS SOFTWARE COMMON 39119E105 19995 388255 388255 230180 0 158075
GUESS INC COMMON 401617105 605 45000 45000 45000 0 0
GUIDANT CORP COMMON 401698105 3111 58005 58005 36265 0 21740
HNC SOFTWARE INC COMMON 40425P107 15685 395200 395200 370800 0 24400
HALLIBURTON CO COMMON 406216101 20550 501220 501220 434310 0 66910
HANDLEMAN CO DEL COMMON 410252100 2600 196250 196250 166250 0 30000
HARMON INDS INC NEW COMMON 413136102 3094 246250 246250 246250 0 0
HARTFORD FINL SVCS GROUP COMMON 416515104 286 7000 7000 7000 0 0
HELIX TECHNOLOGY CORP COMMON 423319102 347 10450 10450 9200 0 1250
HEWLETT PACKARD CO COMMON 428236103 24106 265636 265636 203951 0 61685
HIGH SPEED ACCESS CORP COMMON 42979U102 10624 463160 463160 349035 0 114125
HOLLYWOOD ENTMT CORP COMMON 436141105 559 37250 37250 27750 0 9500
HOME DEPOT INC COMMON 437076102 66905 974933 974933 822904 0 152029
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 223106710 4758402 4758402 3622995 1135407
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 15
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
HOMESTORE COM INC COMMON 437852106 57472 1378640 1378640 1145420 0 233220
HOUSEHOLD INTL INC COMMON 441815107 208 5187 5187 5187 0 0
IDT CORP COMMON 448947101 760 36300 36300 36300 0 0
HYSEQ COMMON 449163302 183 37000 37000 37000 0 0
IMS HEALTH INC COMMON 449934108 903 39600 39600 35100 0 4500
IRT CORP COMMON 450052303 4 15893 15893 0 0 15893
ISS GROUP INC COMMON 450306105 1566 57473 57473 0 0 57473
ITT EDUCATIONAL SERVICES COMMON 45068B109 390 20000 20000 20000 0 0
ITXC CORP COMMON 45069F109 47881 1505100 1505100 1161125 0 343975
IXL ENTERPRISES INC COMMON 450718101 939 26500 26500 26500 0 0
IBIS TECHNOLOGY CORP COMMON 450909106 2070 60000 60000 60000 0 0
ILEX ONCOLOGY INC COMMON 451923106 3418 279050 279050 244050 0 35000
IMAGEX COM INC COMMON 45244D102 369 33000 33000 33000 0 0
IMMUCOR INC COMMON 452526106 186 15500 15500 15500 0 0
IMMUNEX CORP NEW COMMON 452528102 434 10000 10000 10000 0 0
INCO LTD COMMON 453258402 294 13750 13750 3750 0 10000
INFINITY BROADCASTING CP COMMON 45662S102 3608 123100 123100 98900 0 24200
INET TECHNOLOGIES INC COMMON 45662V105 2758 69100 69100 52500 0 16600
INFORMIX CORP COMMON 456779107 480 60500 60500 60500 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 123938493 3786893 3786893 3045432 741461
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 16
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
INFOSPACE COM INC COMMON 45678T102 34345 835130 835130 714220 0 120910
INKTOMI CORP COMMON 457277101 58894 490655 490655 394505 0 96150
INPUT/OUTPUT INC COMMON 457652105 1656 250000 250000 250000 0 0
INSIGHT ENTERPRISES INC COMMON 45765U103 1268 39000 39000 39000 0 0
INSITUFORM TECHNOLOGIES COMMON 457667103 1603 64130 64130 64130 0 0
INSIGHT COMMUNICATIONS I COMMON 45768V108 15026 524940 524940 400650 0 124290
INNKEEPERS USA TR COMMON 4576J0104 108 12950 12950 6800 0 6150
INSWEB CORP COMMON 45809K103 1008 51380 51380 39225 0 12155
INTEL CORP COMMON 458140100 2670 35929 35929 24600 0 11329
INTERACTIVE INTELLIGENCE COMMON 45839M103 1055 45850 45850 20715 0 25135
INTERNAP NETWORK SVCS CO COMMON 45885A102 6810 152595 152595 115605 0 36990
INTERNATIONAL BUSINESS M COMMON 459200101 2138 17666 17666 12266 0 5400
INTERNATIONAL MULTIFOODS COMMON 460043102 794 34500 34500 34500 0 0
INTERNATIONAL RECTIFIER COMMON 460254105 732 48000 48000 48000 0 0
INTERNET CAP GROUP INC COMMON 46059C106 15170 172635 172635 126740 0 45895
INTERNET INITIATIVE JAPA COMMON 46059T109 6978 109025 109025 94875 0 14150
INTERPUBLIC GROUP COS IN COMMON 460690100 1053 25600 25600 14000 0 11600
INTERSPEED INC COMMON 46070W107 821 46600 46600 41700 0 4900
INTERNET COM CORP COMMON 460967102 4260 304270 304270 255895 0 48375
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 157194313 3279140 3279140 2708781 570359
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 17
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
INTUIT COMMON 461202103 42833 488645 488645 401240 0 87405
INVITROGEN CORP COMMON 46185R100 32159 956405 956405 760825 0 195580
IONICS INC COMMON 462218108 1175 36300 36300 36300 0 0
I2 TECHNOLOGIES INC COMMON 465754109 225 5800 5800 5800 0 0
IVAX CORP COMMON 465823102 413 25000 25000 25000 0 0
JDS UNIPHASE CORP COMMON 46612J101 130872 1149892 1149892 920862 0 229030
JAKKS PAC INC COMMON 47012E106 3889 103695 103695 92025 0 11670
JAMESON INNS INC COMMON 470457102 148 17150 17150 1150 0 16000
JOHNSON & JOHNSON COMMON 478160104 8659 94244 94244 57465 0 36779
JONES INTERCABLE INC CL A 480206200 8950 165540 165540 142500 0 23040
JUNIPER NETWORKS INC COMMON 48203R104 28623 157215 157215 102790 0 54425
KLA-TENCORP CORP COMMON 482480100 5850 90000 90000 58000 0 32000
KANA COMMUNICATIONS COMMON 483600102 41057 823190 823190 604180 0 219010
KEMET CORP COMMON 488360108 1698 53100 53100 53100 0 0
KESTREL SOLUTIONS PRIVATE PLACEMEN 492990106 400 125000 125000 0 0 125000
KEYCORP NEW COMMON 493267108 465 18000 18000 0 0 18000
KEYNOTE SYS INC COMMON 493308100 14619 584750 584750 417400 0 167350
KEYSPAN CORP COMMON 49337W100 1258 43965 43965 24815 0 19150
KIMBERLY CLARK CORP COMMON 494368103 450 8530 8530 0 0 8530
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 326015283 4982058 4982058 3719702 1262356
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 18
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
KINDER MORGAN ENERGY PAR COMMON 494550106 602 13900 13900 13900 0 0
KING PHARMACEUTICALS INC COMMON 495582108 41445 1184155 1184155 970440 0 213715
KOPIN CORP COMMON 500600101 766 27600 27600 17500 0 10100
KRONOS INC COMMON 501052104 14949 407482 407482 400727 0 6755
LCA-VISION INC COMMON 501803209 132 24800 24800 24800 0 0
LTX CORP COMMON 502392103 1143 83500 83500 83500 0 0
LABOR READY INC COMMON 505401208 232 23100 23100 900 0 22200
LASON INC COMMON 51808R107 699 15700 15700 15700 0 0
LATITUDE COMMUNICATIONS COMMON 518292107 485 16600 16600 16600 0 0
LAUDER ESTEE COS INC COMMON 518439104 432 11065 11065 4890 0 6175
LEGATO SYS INC COMMON 524651106 4320 99100 99100 0 0 99100
LEXMARK INTL GROUP INC COMMON 529771107 51969 645581 645581 467561 0 178020
LIBERATE TECHNOLOGIES COMMON 530129105 6005 142545 142545 89755 0 52790
LILLY ELI & CO COMMON 532457108 457 7126 7126 2846 0 4280
LINENS N THINGS INC COMMON 535679104 3116 92335 92335 58975 0 33360
LIQUID AUDIO INC COMMON 53631T102 3993 107915 107915 71115 0 36800
LIVING.COM SER B PFD COMMON 538990102 750 79893 79893 0 0 79893
LOISLAW COM INC COMMON 541431102 725 50000 50000 34950 0 15050
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 133474542 3073697 3073697 2294159 779538
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 19
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
LOOKSMART LTD COMMON 543442107 14518 609700 609700 410860 0 198840
LUCENT TECHNOLOGIES INC COMMON 549463107 12790 197155 197155 119213 0 77942
LUMINANT WORLDWIDE CORP COMMON 550260103 1201 39050 39050 35275 0 3775
LYCOS INC COMMON 550818108 16883 336815 336815 280410 0 56405
MCI WORLDCOM INC COMMON 55268B106 24685 343449 343449 249936 0 93513
MDSI MOBILE DATA SOLUTIO COMMON 55268N100 1566 123415 123415 105815 0 17600
MKS INSTRUMENT INC COMMON 55306N104 2837 127500 127500 119700 0 7800
MPSI SYSTEMS (UNRESTR) COMMON 553412206 51 20500 20500 0 0 20500
MACROVISION CORP COMMON 555904101 11776 265380 265380 246300 0 19080
MADDEN STEVEN LTD COMMON 556269108 486 37600 37600 37600 0 0
MAKER COMMUNICATIONS INC COMMON 560875106 27633 1175880 1175880 922280 0 253600
MAMAMEDIA SER D COMMON 561994104 903 167220 167220 74627 0 92593
MANDALAY RESORT GROUP COMMON 562567107 1110 56200 56200 56200 0 0
MARINE DRILLING COS INC COMMON 568240204 1864 117900 117900 102900 0 15000
MARSH & MCLENNAN COS INC COMMON 571748102 4151 60600 60600 52500 0 8100
MASTEC INC COMMON 576323109 783 26600 26600 26600 0 0
MATHSOFT INC COMMON 576798102 51 20000 20000 0 0 20000
LOOKSMART, LTD SER C PFD COMMON 576990105 5715 300000 300000 0 0 300000
MAXIM INTEGRATED PRODS I COMMON 57772K101 11182 177225 177225 145670 0 31555
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 142578473 4241706 4241706 2995754 1245942
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 20
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
MCGRAW HILL COS INC COMMON 580645109 48085 994010 994010 819000 0 175010
MCLEODUSA INC COMMON 582266102 13194 310000 310000 187100 0 122900
MEDIAONE GROUP INC COMMON 58440J104 2770 40555 40555 8755 0 31800
MEDIAONE GROUP INC PFD CV 58440J203 305 2256 2256 0 0 2256
MEDIA METRIX INC COMMON 58440X103 4344 62175 62175 39155 0 23020
MEDICIS PHARMACEUTICAL C COMMON 584690309 721 25300 25300 25300 0 0
MEDIMMUNE INC COMMON 584699102 19914 199830 199830 176465 0 23365
MEDQUIST INC COMMON 584949101 1876 56110 56110 28300 0 27810
MEDTRONIC INC COMMON 585055106 39859 1120810 1120810 959490 0 161320
MENTOR CORP MINN COMMON 587188103 1200 42100 42100 42100 0 0
MERCK & CO INC COMMON 589331107 1057 16316 16316 7340 0 8976
METRICOM INC COMMON 591596101 3201 140700 140700 140700 0 0
METROMEDIA FIBER NETWORK COMMON 591689104 7403 302160 302160 232800 0 69360
MICREL INC COMMON 594793101 206 4750 4750 4750 0 0
MICROS SYS INC COMMON 594901100 644 15900 15900 15300 0 600
MICROSOFT CORP COMMON 594918104 125699 1387979 1387979 1132545 0 255434
MICROCELL TELECOMMUNICAT COMMON 59501T304 4044 311100 311100 198200 0 112900
MICROMUSE INC COMMON 595094103 90459 1407920 1407920 1143225 0 264695
MILLENNIUM PHARMACEUTICA COMMON 599902103 3012 46340 46340 24835 0 21505
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 370844450 6529033 6529033 5199860 1329173
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 21
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
MINNESOTA MNG & MFG CO COMMON 604059105 406 4224 4224 470 0 3754
MIPS TECHNOLOGIES INC COMMON 604567107 26088 820060 820060 642355 0 177705
MOBIL CORP COMMON 607059102 1005 9976 9976 2150 0 7826
MOBILE MINI INC COMMON 60740F105 615 28100 28100 28100 0 0
MODEM MEDIA POPPE TYSON COMMON 607533106 481 13000 13000 10500 0 2500
MONTANA POWER CO COMMON 612085100 9163 301040 301040 201375 0 99665
MORGAN J P & CO INC COMMON 616880100 253 2217 2217 0 0 2217
MORTGAGE COM INC COMMON 61910V102 1938 201400 201400 132500 0 68900
MOTOROLA INC/CV/LYON BND CV 620076AE9 403 250000 250000 250000 0 0
MP3 COM INC COMMON 62473M109 2340 62300 62300 42745 0 19555
MYPOINTS COM INC COMMON 62855T102 3283 230400 230400 214675 0 15725
NCO GROUP INC COMMON 628858102 13719 291900 291900 291900 0 0
NTL INC COMMON 629407107 701 7300 7300 7300 0 0
NABORS INDS INC COMMON 629568106 7018 280701 280701 221476 0 59225
NATIONAL COMPUTER SYS IN COMMON 635519101 9954 259600 259600 259600 0 0
NATIONAL INFO CONSORTIUM COMMON 636491102 12018 486810 486810 437335 0 49475
NATIONAL SEMICONDUCTOR C COMMON 637640103 20820 681215 681215 584275 0 96940
NATURAL MICROSYSTEMS COR COMMON 638882100 1086 78300 78300 49700 0 28600
NAVIGANT CONSULTING INC COMMON 63935N107 15786 340389 340389 290514 0 49875
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 127691992 4367657 4367657 3676120 691537
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 22
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
NETBANK INC COMMON 640933107 1064 48075 48075 47940 0 135
NET2PHONE COMMON 64108N106 79265 1520680 1520680 1251240 0 269440
NETEGRITY (RESTR) COMMON 64110P107 11412 468185 468185 375338 0 92847
NETEGRITY, INC. COMMON 64110P909 2131 97135 97135 63138 0 33997
NETGRAVITY INC COMMON 641114103 2252 68100 68100 54250 0 13850
NETOPIA INC COMMON 64114K104 39988 1002825 1002825 846360 0 156465
NETRO CORP COMMON 64114R109 1809 66100 66100 53900 0 12200
NETIQ CORP COMMON 64115P102 320 10790 10790 7020 0 3770
NETWORK APPLIANCE INC COMMON 64120L104 64741 903895 903895 746685 0 157210
NETWORK SOLUTIONS INC DE COMMON 64121Q102 13887 151150 151150 108950 0 42200
NETZERO INC COMMON 64122R109 8219 316105 316105 184370 0 131735
NEW YORK TIMES CO COMMON 650111107 653 17400 17400 17400 0 0
NEWMONT MINING CORP COMMON 651639106 5971 230750 230750 206550 0 24200
NEWPARK RES INC COMMON 651718504 775 100000 100000 100000 0 0
NEXTCARD INC COMMON 65332K107 16887 689245 689245 496155 0 193090
NEXTEL COMMUNICATIONS IN COMMON 65332V103 264 3900 3900 2700 0 1200
NEXTLINK COMMUNICATIONS COMMON 65333H707 3731 71970 71970 56450 0 15520
NOBLE AFFILIATES INC COMMON 654894104 50585 1744320 1744320 1456260 0 288060
NOKIA CORP COMMON 654902204 63466 706155 706155 566030 0 140125
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 367114089 8159145 8159145 6595598 1563547
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 23
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
NOBLE DRILLING CORP COMMON 655042109 17949 820530 820530 664755 0 155775
NORTEL NETWORKS CORP COMMON 656569100 782 15334 15334 0 0 15334
NINTENDO COMMON 6639550 3333 20900 20900 13400 0 7500
NORTHPOINT COMMUNICATION COMMON 666610100 32966 1781965 1781965 1466805 0 315160
NOVA CORP GA COMMON 669784100 953 38100 38100 37000 0 1100
OFFICEMAX INC COMMON 67622M108 58 10000 10000 0 0 10000
SOFTBANK CORP COMMON 6770620 19970 52500 52500 35700 0 16800
OMNICARE INC COMMON 681904108 550 57100 57100 57100 0 0
OMNICOM GROUP INC COMMON 681919106 673 8500 8500 7300 0 1200
OMNIPOINT CORP COMMON 68212D102 14388 257500 257500 190200 0 67300
1 800 FLOWERS COM COMMON 68243Q106 1214 84085 84085 64635 0 19450
OPTICAL COATING LAB INC COMMON 683829105 12097 131400 131400 108500 0 22900
O REILLY AUTOMOTIVE INC COMMON 686091109 574 12045 12045 12045 0 0
OSTEOTECH INC COMMON 688582105 727 53354 53354 41979 0 11375
OUTBACK STEAKHOUSE INC COMMON 689899102 24357 956343 956343 719208 0 237135
P-COM INC COMMON 693262107 4138 591200 591200 378600 0 212600
PE CORP - BIO GROUP COMMON 69332S102 128263 1775265 1775265 1460220 0 315045
PE CORP - CELERA GEN COMMON 69332S201 30653 761565 761565 594240 0 167325
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 295345724 7473224 7473224 5869587 1603637
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 24
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
P F CHANGS CHINA BISTRO COMMON 69333Y108 1547 71530 71530 50085 0 21445
PMC-SIERRA INC COMMON 69344F106 6015 65025 65025 36200 0 28825
PACIFIC SUNWEAR CALIF IN COMMON 694873100 1416 50500 50500 50500 0 0
PAIRGAIN TECHNOLOGIES IN COMMON 695934109 375 29400 29400 29400 0 0
PARADYNE NETWORKS INC COMMON 69911G107 12194 435505 435505 320920 0 114585
PARAMETRIC TECHNOLOGY CO COMMON 699173100 2569 190325 190325 177950 0 12375
PATTERSON ENERGY INC COMMON 703414102 814 53600 53600 53600 0 0
PCORDER COM INC COMMON 70453H107 3049 86800 86800 55800 0 31000
PEGASUS SYSTEMS INC COMMON 705906105 319 8500 8500 7500 0 1000
PERFORMANCE TECHNOLOGIES COMMON 71376K102 470 20850 20850 20850 0 0
PERITUS SOFTWARE SVC COMMON 714006103 1 10088 10088 0 0 10088
PERSISTENCE SOFTWARE INC COMMON 715329108 14221 497905 497905 365955 0 131950
PETROLEUM GEO-SVCS A/S COMMON 716597109 30950 1623595 1623595 1377895 0 245700
PFIZER INC COMMON 717081103 12843 357990 357990 230940 0 127050
PHELPS DODGE CORP COMMON 717265102 501 9100 9100 6600 0 2500
PHONE COM INC COMMON 71920Q100 205893 1359030 1359030 1071935 0 287095
PINNACLE SYS INC COMMON 723481107 5916 139600 139600 119600 0 20000
PIXAR COMMON 725811103 11767 312750 312750 306550 0 6200
PLACER DOME INC COMMON 725906101 5302 356450 356450 314450 0 42000
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 318199790 5712943 5712943 4615230 1097713
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 25
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
PLAYBOY ENTERPRISES INC COMMON 728117300 4556 170735 170735 164335 0 6400
POLAROID CORP COMMON 731095105 13562 521625 521625 401770 0 119855
POLYCOM INC COMMON 73172K104 15631 327995 327995 282450 0 45545
PORTAL SOFTWARE INC COMMON 736126103 12898 332860 332860 299530 0 33330
POTOMAC ELEC PWR CO COMMON 737679100 513 20150 20150 17300 0 2850
POWER-ONE INC COMMON 739308104 576 22600 22600 22600 0 0
POWERWAVE TECHNOLOGIES I COMMON 739363109 2556 53000 53000 40000 0 13000
POWERTEL INC COMMON 73936C109 31634 574510 574510 447130 0 127380
PRECISION DRILLING CORP COMMON 74022D100 290 12500 12500 12500 0 0
PRENTISS PPTYS TR COMMON 740706106 479 21575 21575 7950 0 13625
PREVIEW TRAVEL INC COMMON 74137R101 813 50000 50000 50000 0 0
PRICELINE COM INC COMMON 741503106 24617 381665 381665 275985 0 105680
PRIORITY HEALTHCARE CORP COMMON 74264T102 818 26500 26500 26500 0 0
PROBUSINESS SERVICES INC COMMON 742674104 4033 150080 150080 117975 0 32105
PROCTER & GAMBLE CO COMMON 742718109 357 3804 3804 0 0 3804
PROFIT RECOVERY GROUP IN COMMON 743168106 7095 159000 159000 159000 0 0
DYAX CORP PFD CV 743997892 103 28944 28944 28944 0 0
PROXICOM INC COMMON 744282104 17796 304200 304200 304200 0 0
PROXIM INC COMMON 744284100 856 18600 18600 18600 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 140578351 3196243 3196243 2676769 519474
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 26
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
PURCHASEPRO COM COMMON 746144104 2770 79700 79700 74300 0 5400
QLT PHOTOTHERAPEUTICS IN COMMON 746927102 39978 523010 523010 422955 0 100055
QRS CORP COMMON 74726X105 3232 50400 50400 40500 0 9900
QLOGIC CORP COMMON 747277101 19808 283725 283725 194535 0 89190
QUALCOMM INC COMMON 747525103 1419 7500 7500 7500 0 0
QUEST SOFTWARE INC COMMON 74834T103 16597 356925 356925 243800 0 113125
QUOTESMITH COM INC COMMON 749117107 178 25000 25000 24300 0 700
QWEST COMMUNICATIONS INT COMMON 749121109 29719 1005292 1005292 768520 0 236772
R & B FALCON CORP COMMON 74912E101 28966 2206935 2206935 1759225 0 447710
RCN CORP COMMON 749361101 41820 1019999 1019999 819438 0 200561
RSA SEC INC COMMON 749719100 1774 66800 66800 43400 0 23400
RF MICRODEVICES INC COMMON 749941100 6158 134600 134600 134600 0 0
RAMP NETWORKS INC COMMON 751567108 10102 459200 459200 426700 0 32500
RARE HOSPITALITY INTL IN COMMON 753820109 789 36490 36490 36490 0 0
RAVISENT TECHNOLOGIES IN COMMON 754440105 26216 1823690 1823690 1378960 0 444730
REALNETWORKS INC COMMON 75605L104 33672 322030 322030 238830 0 83200
RED HAT INC COMMON 756577102 28300 294790 294790 206820 0 87970
REDBACK NETWORKS INC COMMON 757209101 108224 1002072 1002072 721685 0 280387
REMEC INC COMMON 759543101 483 35100 35100 35100 0 0
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 399568373 9771058 9771058 7616558 2154500
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 27
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
REMEDY CORP COMMON 759548100 2247 79200 79200 79200 0 0
RESEARCH IN MOTION LTD COMMON 760975102 4517 146000 146000 106800 0 39200
REUTERS GROUP PLC COMMON 76132M102 362 5250 5250 5000 0 250
RHYTHMS NETCONNECTIONS I COMMON 762430205 65818 1907755 1907755 1603310 0 304445
ROGERS CANTEL MOBILE COM COMMON 775102205 3683 155500 155500 99100 0 56400
ROWAN COS INC COMMON 779382100 828 50950 50950 50950 0 0
ROYAL DUTCH PETE CO COMMON 780257804 1767 29912 29912 8661 0 21251
RURAL CELLULAR CORP COMMON 781904107 514 11200 11200 11200 0 0
SBC COMMUNICATIONS INC COMMON 78387G103 1684 32986 32986 4000 0 28986
SALEM COMMUNICATIONS COR CL A 794093104 1802 70650 70650 60950 0 9700
SANTA CRUZ OPERATION INC COMMON 801833104 1698 142200 142200 91400 0 50800
SAWTEK INC COMMON 805468105 1365 39000 39000 39000 0 0
SBS BROADCASTING SA BOND CV 805906AB0 552 390000 390000 390000 0 0
SCHERING PLOUGH CORP COMMON 806605101 3386 77620 77620 64320 0 13300
SCHLUMBERGER LTD COMMON 806857108 61937 993974 993974 769280 0 224694
SCIENT CORP COMMON 80864H109 9968 155750 155750 105600 0 50150
SEAGRAM LTD COMMON 811850106 21122 464210 464210 437740 0 26470
SEMTECH CORP COMMON 816850101 1267 34600 34600 22400 0 12200
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 185119882 4801887 4801887 3955391 846496
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 28
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
SEPRACOR INC COMMON 817315104 36846 488020 488020 425205 0 62815
SEROLOGICALS CORP COMMON 817523103 1450 341180 341180 305455 0 35725
SHELL TRANS & TRADING PL COMMON 822703609 237 5200 5200 5200 0 0
SIEBEL SYS INC COMMON 826170102 16478 247320 247320 234090 0 13230
SILVERSTREAM SOFTWARE IN COMMON 827907106 4422 142075 142075 94640 0 47435
SILVERSTREAM SER D PFD COMMON 828990101 8518 342105 342105 57530 0 284575
SILVERSTREAM SOFTWARE COMMON 828995100 11344 455581 455581 455581 0 0
SINCLAIR BROADCAST GROUP COMMON 829226109 136 15000 15000 0 0 15000
SITARA NETWORKS SER E COMMON 829990100 700 181818 181818 0 0 181818
SMITH INTL INC COMMON 832110100 23419 578240 578240 474220 0 104020
SOFTECH INC COMMON 834021107 48 31000 31000 0 0 31000
SONIC CORP COMMON 835451105 652 21430 21430 21430 0 0
SONY CORP COMMON 835699307 150127 1000430 1000430 804180 0 196250
WOMEN.COM SER E PFD COMMON 837990100 125 12540 12540 10178 0 2362
SPRINT CORP COMMON 852061100 1273 23470 23470 3500 0 19970
SPRINT CORP COMMON 852061506 1573 21093 21093 16100 0 4993
STAMPS COM INC COMMON 852857101 15066 433540 433540 381590 0 51950
STAPLES INC COMMON 855030102 51415 2357118 2357118 2049009 0 308109
STARMEDIA NETWORK INC COMMON 855546107 4621 125845 125845 105345 0 20500
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 329467256 6858456 6858456 5454753 1403703
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 29
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
STATE STR CORP COMMON 857477103 871 13484 13484 11950 0 1534
STMICROELECTRONICS N V COMMON 861012102 281 3800 3800 0 0 3800
STREAMLINE COM INC COMMON 863239109 911 112500 112500 112500 0 0
STUDENT ADVANTAGE INC COMMON 86386Q105 4214 366450 366450 283500 0 82950
SUN MICROSYSTEMS INC COMMON 866810104 12466 134040 134040 119400 0 14640
SYKES ENTERPRISES INC COMMON 871237103 509 20600 20600 20600 0 0
SYMANTEC CORP COMMON 871503108 1917 53300 53300 53300 0 0
SYMBOL TECHNOLOGIES INC COMMON 871508107 10581 314678 314678 281093 0 33585
SYNOPSYS INC COMMON 871607107 281 5000 5000 5000 0 0
TBA ENTMT CORP COMMON 872173109 163 40100 40100 40100 0 0
TJX COS INC NEW COMMON 872540109 1198 42680 42680 24430 0 18250
TSI INTERNATIONAL SOFTWA COMMON 872879101 6723 247862 247862 204042 0 43820
TLC THE LASER CTR INC COMMON 872934104 10221 415065 415065 319120 0 95945
TMP WORLDWIDE INC COMMON 872941109 2009 33000 33000 31000 0 2000
TALK CITY INC COMMON 874263106 101 11890 11890 7890 0 4000
TANDY CORP COMMON 875382103 1165 22540 22540 20840 0 1700
TANNING TECHNOLOGY CORP COMMON 87588P101 7180 273520 273520 237050 0 36470
TECH DATA CORP COMMON 878237106 519 22300 22300 22300 0 0
TEKELEC COMMON 879101103 519 37600 37600 37600 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 62247541 2185109 2185109 1840615 344494
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 30
- -------------------------------------------------------------------------- ---------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- -------------------------------------------------------------------------- ---------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
TELEFONOS DE MEXICO S A COMMON 879403780 356 500 500 0 0 5000
TELETECH HOLDINGS INC COMMON 879939106 811 56900 56900 56900 0 0
TELESYSTEM INTL WIRELESS COMMON 879946101 13030 766485 766485 578825 0 187660
TENFOLD CORP COMMON 88033A103 15521 585685 585685 475315 0 110370
TERADYNE INC COMMON 880770102 39350 1116321 1116321 937940 0 178381
TEXACO INC COMMON 881694103 394 6240 6240 500 0 5740
TEXAS INSTRS INC COMMON 882508104 24946 303295 303295 243680 0 59615
TICKETMASTER ONLINE-CITY COMMON 88633P203 7205 297900 297900 256900 0 41000
TIME WARNER INC COMMON 887315109 16179 266325 266325 221685 0 44640
TIME WARNER TELECOM INC COMMON 887319101 9639 461730 461730 418320 0 43410
TIMES MIRROR CO NEW COMMON 887364107 932 14165 14165 6790 0 7375
TIVO INC COMMON 888706108 10269 343025 343025 283645 0 59380
TOO INC COMMON 890333107 689 38412 38412 38412 0 0
TRANSWITCH CORP COMMON 894065101 915 16050 16050 16050 0 0
TRIANGLE PHARMACEUTICALS COMMON 89589H104 1983 103000 103000 85900 0 17100
TRIDENT MICROSYSTEMS INC COMMON 895919108 1709 207200 207200 133300 0 73900
TRIBUNE CO NEW COMMON 896047107 1502 30200 30200 30200 0 0
TRINTECH GROUP PLC COMMON 896682101 852 64900 64900 52255 0 12645
TUESDAY MORNING CORP COMMON 899035505 583 23100 23100 23100 0 0
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 147744151 4725333 4725333 3870817 854516
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 31
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
TUMBLEWEED COMMUNICATION COMMON 899690101 1057 39500 39500 35355 0 4145
TWEETER HOME ENTMT GROUP COMMON 901167106 12616 337560 337560 278280 0 59280
TYCO INTL LTD NEW COMMON 902124106 27016 261652 261652 205940 0 55712
USA NETWORKS INC COMMON 902984103 12321 317950 317950 279650 0 38300
UTI ENERGY CORP COMMON 903387108 1551 79800 79800 78800 0 1000
US ONCOLOGY INC COMMON 90338W103 468 51600 51600 51600 0 0
UNION PAC RES GROUP INC COMMON 907834105 1365 84000 84000 84000 0 0
UNITED PAN-EUROPE COMMUN COMMON 911300200 2974 48750 48750 40450 0 8300
UNITED TECHNOLOGIES CORP COMMON 913017109 6087 102624 102624 81074 0 21550
UNITEDGLOBALCOM COMMON 913247508 6979 97435 97435 72765 0 24670
UNIVISION COMMUNICATIONS COMMON 914906102 439 5400 5400 2800 0 2600
USWEB CORP COMMON 917327108 3877 113000 113000 73800 0 39200
VANS INC COMMON 921930103 252 21000 21000 21000 0 0
VARCO INTL INC COMMON 922126107 11850 972295 972295 772450 0 199845
VARIAN INC COMMON 922206107 591 33300 33300 33300 0 0
VASTAR RES INC COMMON 922380100 14394 230075 230075 167990 0 62085
VERITAS SOFTWARE CO COMMON 923436109 59527 783898 783898 722103 0 61795
VERITY INC COMMON 92343C106 2560 37200 37200 37200 0 0
VERISIGN INC COMMON 92343E102 136563 1282280 1282280 990825 0 291455
--------- ------- ------- ------ ------ -------- ------ ------
COLUMN TOTALS 305228879 4930319 4930319 4043782 886537
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 32
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
VERISITY LTD SER D PFD COMMON 923991103 500 67884 67884 0 0 67884
VERSATEL TELECOM INTL N COMMON 925301103 332 30900 30900 29290 0 1610
VERTICALNET INC COMMON 92532L107 9659 261060 261060 175960 0 85100
VIACOM INC/CL B COMMON 925524308 24894 589205 589205 475665 0 113540
VIATEL INC COMMON 925529208 1670 56500 56500 48800 0 7700
VIANT CORP COMMON 92553N107 2028 41930 41930 30050 0 11880
VIGNETTE CORP COMMON 926734104 98914 1092976 1092976 741416 0 351560
VINTAGE PETE INC COMMON 927460105 184 13610 13610 13310 0 300
VISUAL NETWORKS INC COMMON 928444108 1108 26109 26109 26109 0 0
VISX INC DEL COMMON 92844S105 34181 432160 432160 354065 0 78095
VITESSE SEMICONDUCTOR CO COMMON 928497106 23117 270770 270770 232295 0 38475
VITRIA TECHNOLOGY COMMON 92849Q104 256 6975 6975 2555 0 4420
VOICESTREAM WIRELESS COR COMMON 928615103 43477 704445 704445 556030 0 148415
WAL MART STORES INC COMMON 931142103 24549 516147 516147 402695 0 113452
WALGREEN CO COMMON 931422109 1741 68630 68630 57530 0 11100
WARNER LAMBERT CO COMMON 934488107 5567 83870 83870 72670 0 11200
WATERS CORP COMMON 941848103 38488 635515 635515 545325 0 90190
WEATHERFORD INTL INC COMMON 947074100 790 24700 24700 22700 0 2000
WEBSTAKES COM INC COMMON 94768K100 148 16700 16700 3000 0 13700
--------- ------- ------- ------ ------ -------- ------ -------
COLUMN TOTALS 313668132 4974283 4974283 3812465 1161818
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 33
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
WELLS FARGO & CO NEW COMMON 949746101 262 6600 6600 6600 0 0
WILDFIRE COMM WRTS COMMON 967990102 0 400000 400000 90000 0 310000
WILDFIRE COMMUNICATIONS COMMON 967991100 2000 400000 400000 90000 0 310000
WILLIAMS COS INC DEL COMMON 969457100 87752 2332277 2332277 1898462 0 433815
WINK COMMUNICATIONS COMMON 974168106 14926 341650 341650 278460 0 63190
WINSTAR COMMUNICATIONS I COMMON 975515107 83463 2136640 2136640 1745835 0 390805
WOMEN.COM NETWORKS COMMON 978990109 1824 182370 182370 148020 0 34350
WORLDGATE COMMUNICATIONS COMMON 98156L307 202 8845 8845 5735 0 3110
XILINX INC COMMON 983919101 38311 584620 584620 529120 0 55500
XIRCOM INC COMMON 983922105 1929 45200 45200 45200 0 0
XEROX CORP COMMON 984121103 205 4884 4884 4884 0 0
YAHOO INC COMMON 984332106 181659 1012027 1012027 755162 0 256865
YOUNG & RUBICAM INC COMMON 987425105 6028 137000 137000 136700 0 300
YOUNG BROADCASTING INC COMMON 987434107 335 6400 6400 0 0 6400
ZALE CORP NEW COMMON 988858106 1563 40800 40800 40800 0 0
ZONAGEN INC COMMON 98975L108 158 53950 53950 33250 0 20700
ZOLL MED CORP COMMON 989922109 4984 164750 164750 138250 0 26500
INSTINCTIVE TECH SER C COMMON 9B999J975 2000 416667 416667 0 0 416667
AMDOCS LTD COMMON G02602103 64255 3059780 3059780 2585815 0 473965
--------- -------- -------- ------ ------ -------- ------ -------
COLUMN TOTALS 493288531 11366493 11366493 8549693 2816800
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F 9/30/99
REPORTING MANAGER: ESSEX INVESTMENT MGMT CO PAGE 34
- ------------------------------------------------------------------------------------------------------------------------------------
ITEM 1 ITEM 2 ITEM 3 ITEM 4 ITEM 5 ITEM 6 ITEM 7 ITEM 8
NAME OF ISSUER TITLE CUSIP FAIR SHARES OR INVESTMENT DISCRETION MANA- VOTING AUTHORITY
OF NUMBER MARKET PRINCIPAL SHARED GERS
CLASS VALUE AMOUNT SHARED- SHARED OTHER SOLE SHARED NONE
DEFINED (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
GEMSTAR INTL GROUP LTD COMMON G3788V106 40959 524278 524278 395818 0 128460
GLOBALSTAR TELECOMMUNICT COMMON G3930H104 3698 160800 160800 140000 0 20800
RSL COMMUNICATIONS LTD COMMON G7702U102 8836 484160 484160 432200 0 51960
SANTA FE INTL CORP COMMON G7805C108 20368 944595 944595 780285 0 164310
TRANSOCEAN OFFSHORE INC COMMON G90076103 1678 54790 54790 32520 0 22270
AUDIOCODES LTD COMMON M15342104 4666 124010 124010 98810 0 25200
COMMTOUCH SOFTWARE LTD COMMON M25596103 418 28075 28075 16300 0 11775
GALILEO TECHNOLOGY LTD COMMON M47298100 558 22300 22300 22300 0 0
ASM LITHOGRAPHY HLDG N V COMMON N07059111 3625 54050 54050 34950 0 19100
INDIGO N V COMMON N44495104 247 47652 47652 36979 0 10673
PACIFIC INTERNET LTD COMMON Y66183107 201 6295 6295 4425 0 1870
---------- --------- ---------- ------ ------ --------- ------ --------
COLUMN TOTALS 86881615 2494755 2494755 2019162 475593
---------- --------- ---------- ------ ------ --------- ------ --------
7334141995 161874868 161874868 127055499 34819369
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</TABLE>
