<PAGE>
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13-F
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: 3/31/99
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Check here if Amendment [ ]; Amendment Number:
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This Amendment (Check only one.): [ ] is a restatement.
[ ] adds new holdings entries.
Institutional Investment Manager Filing this Report:
Name: Essex Investment Management Co.
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Address:
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Form 13F File Number: 28-
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The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.
Person Signing this Report on Behalf of Reporting Manager:
Name:
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Title:
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Phone:
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Signature, Place, and Date of Signing:
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[Signature] [City, State] [Date]
Report Type (Check only one.):
[X] 13F HOLDINGS REPORT. (Check here if all holdings of this reporting
manager are reported in this report.)
[ ] 13F NOTICE. (Check here if no holdings reported are in this report, and
all holdings are reported by other reporting manager(s).)
[ ] 13F COMBINATION REPORT. (Check here if a portion of the holdings for this
reporting manager are reported in this report and a portion are reported
by other reporting manager(s).)
List of Other Managers Reporting for this Manager:
Form 13F File Number Name
28-
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Page 1
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
AGCO CORP COMMON 001084102 66 10000 10000 0 0 10000
AT&T CORP COMMON 001957208 2726 51830 51830 49930 0 1900
ABACUS DIRECT CORP COMMON 002553105 8649 105480 105480 79080 0 26400
ABBOTT LABS COMMON 002824100 3198 68315 68315 24915 0 43400
ABERCROMBIE & FITCH CO COMMON 002896207 15329 166165 166165 125695 0 40470
ABOVENET COMMUNICATIONS COMMON 003743101 18917 144545 144545 115345 0 29200
ACTION PERFORMANCE COS COMMON 004933107 1806 59950 59950 59950 0 0
ADELPHIA COMMUNICATIONS COMMON 006848105 17991 285575 285575 231300 0 54275
ADVANCE PARADIGM INC COMMON 007491103 51745 818905 818905 697505 0 121400
ADVANCED MARKETING SVCS COMMON 00753T105 410 31550 31550 31550 0 0
ADVANTAGE LEARNING SYSTE COMMON 00757K100 54637 1758926 1758926 1451706 0 307220
AETNA INC COMMON 008117103 295 3549 3549 0 0 3549
AIRTOUCH COMMUNICATNS COMMON 00949T100 242 2505 2505 2505 0 0
ALBANY MOLECULAR RESH IN COMMON 012423109 4356 174235 174235 140260 0 33975
ALLAIRE CORP COMMON 016714107 32242 474140 474140 390615 0 83525
ALLEGIANCE TELECOM INC COMMON 01747T102 22343 893730 893730 718630 0 175100
ALLTEL CORP COMMON 020039103 1564 25078 25078 14630 0 10448
ALPHA 1 BIOMEDICALS INC COMMON 020910105 10 112000 112000 0 0 112000
AMAZON COM INC COMMON 023135106 166567 967358 967358 729513 0 237845
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 2
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
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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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
AMERICA ONLINE INC DEL COMMON 02364J104 186826 1270922 1270922 1005755 0 265167
AMERICAN BIOGENETIC SCIE COMMON 024611105 13 10000 10000 0 0 10000
AMERICAN EXPRESS CO COMMON 025816109 4767 40482 40482 29930 0 10552
AMERICAN GENERAL CORP COMMON 026351106 810 11488 11488 0 0 11488
AMERICAN HOME PRODS CORP COMMON 026609107 10533 161425 161425 71710 0 89715
AMERICAN INTL GROUP INC COMMON 026874107 71978 596708 596708 500225 0 96483
AMERICAN TOWER CORP COMMON 029912201 730 29810 29810 0 0 29810
AMGEN INC COMMON 031162100 4799 64100 64100 56500 0 7600
ANADARKO PETE CORP COMMON 032511107 49017 1298465 1298465 1073880 0 224585
ANESTA CORP COMMON 034603100 3170 140500 140500 125500 0 15000
ANHEUSER BUSCH COS INC COMMON 035229103 13073 171730 171730 132240 0 39490
AON CORP COMMON 037389103 949 15000 15000 0 0 15000
APACHE CORP COMMON 037411105 8685 333231 333231 298831 0 34400
APPLIED MATLS INC COMMON 038222105 3851 62425 62425 49300 0 13125
ARTHROCARE CORP COMMON 043136100 177 10754 10754 2560 0 8194
ASCEND COMMUNICATIONS COMMON 043491109 1464 17493 17493 0 0 17493
ASPECT DEV INC COMMON 045234101 10683 459505 459505 421455 0 38050
AT HOME CORP COMMON 045919107 32323 205225 205225 160650 0 44575
AT ENTMT INC COMMON 045920105 285 30000 30000 30000 0 0
AUTOBYTEL COM INC COMMON 05275N106 1429 34126 34126 23891 0 10235
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 3
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
AVANT IMMUNOTHERAPEUTICS COMMON 053491106 47 30000 30000 0 0 30000
AVID TECHNOLOGY INC COMMON 05367P100 1233 70700 70700 70700 0 0
AWARE INC COMMON 05453N100 4700 100000 100000 100000 0 0
AXENT TECHNOLOGIES INC COMMON 05459C108 737 30625 30625 0 0 30625
BJ SVCS CO COMMON 055482103 22640 973780 973780 795380 0 178400
BP AMOCO P L C COMMON 055622104 1991 19709 19709 2024 0 17685
BAKER HUGHES INC COMMON 057224107 9083 373590 373590 344840 0 28750
BANK AMER CORP COMMON 060505104 290 4100 4100 0 0 4100
BARCLAYS BK PLC COMMON 06738C505 202 7450 7450 0 0 7450
BED BATH & BEYOND INC COMMON 075896100 3187 87305 87305 52205 0 35100
BELL ATLANTIC CORP COMMON 077853109 789 15263 15263 2695 0 12568
BEYOND COM CORP COMMON 08860E101 2703 103200 103200 85000 0 18200
BINDVIEW DEV CORP COMMON 090327107 3084 99100 99100 94600 0 4500
BIOGEN INC COMMON 090597105 14140 123700 123700 107840 0 15860
BLOCK H & R INC COMMON 093671105 366 7733 7733 5500 0 2233
BOSTON SCIENTIFIC CORP COMMON 101137107 6504 160100 160100 141500 0 18600
BOTTOMLINE TECH DEL INC COMMON 101388106 2814 44100 44100 27200 0 16900
BRIGHT HORIZON FAMILY SO COMMON 109195107 14657 670020 670020 475794 0 194226
BRISTOL MYERS SQUIBB CO COMMON 110122108 2371 36968 36968 17700 0 19268
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 4
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
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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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
BROADCAST COM INC COMMON 111310108 26560 224730 224730 166955 0 57775
BROADCOM CORP COMMON 111320107 2222 36060 36060 13580 0 22480
BUFFETS INC COMMON 119882108 1993 201800 201800 201800 0 0
BURLINGTON RES INC COMMON 122014103 23903 598505 598505 496410 0 102095
BURNHAM PACIFIC PPTYS COMMON 12232C108 245 23625 23625 775 0 22850
CBT GROUP PUB LTD COMMON 124853300 22379 1956620 1956620 1551770 0 404850
CBS CORP COMMON 12490K107 8045 197130 197130 174630 0 22500
CDNOW N2K INC COMMON 125086108 1708 105950 105950 68700 0 37250
C H ROBINSON WORLDWIDE I COMMON 12541W100 750 29475 29475 28850 0 625
CMGI INC COMMON 125750109 223415 1220430 1220430 991955 0 228475
CNET INC COMMON 125945105 27969 303600 303600 262300 0 41300
CSK AUTO CORP COMMON 125965103 24910 832065 832065 727315 0 104750
CSG SYS INTL INC COMMON 126349109 3944 100000 100000 100000 0 0
CVS CORP COMMON 126650100 53644 1129346 1129346 889576 0 239770
CABLEVISION SYS CORP COMMON 12686C109 425 5740 5740 2440 0 3300
CABOT CORP COMMON 127055101 241 11325 11325 11325 0 0
CARDINAL HEALTH INC COMMON 14149Y108 5132 77753 77753 46793 0 30960
CAREER EDUCATION CORP COMMON 141665109 374 10800 10800 3300 0 7500
CELESTIAL SEASONINGS INC COMMON 151016102 24242 1121015 1121015 874680 0 246335
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 5
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
CENTOCOR INC COMMON 152342101 2286 61900 61900 54600 0 7300
CENTRAL PKG CORP COMMON 154785109 207 6000 6000 6000 0 0
CENTURY TEL ENTERPRISES COMMON 156686107 6592 93835 93835 70580 0 23255
CHANCELLOR MEDIA CORP COMMON 158915108 4647 98600 98600 86500 0 12100
CHASE MANHATTAN CORP NEW COMMON 16161A108 463 5694 5694 5694 0 0
CHECKFREE HLDGS CORP COMMON 162816102 3903 91712 91712 40550 0 51162
CHEVRON CORPORATION COMMON 166751107 676 7622 7622 1690 0 5932
CHUBB CORP COMMON 171232101 351 6000 6000 0 0 6000
CIENA CORP COMMON 171779101 5802 257850 257850 228550 0 29300
CINAR CORP COMMON 171905201 1107 50000 50000 50000 0 0
CINAR CORP COMMON 171905300 1524 66250 66250 49850 0 16400
CISCO SYS INC COMMON 17275R102 36054 329076 329076 274257 0 54819
CIRCUS CIRCUS ENTERPRISE COMMON 172909103 680 38700 38700 38700 0 0
CITIGROUP INC COMMON 172967101 381 5960 5960 5960 0 0
CLEAR CHANNEL COMMUNICAT COMMON 184502102 5613 83700 83700 72200 0 11500
CLOROX CO DEL COMMON 189054109 642 5475 5475 3225 0 2250
COCA COLA CO COMMON 191216100 1778 28971 28971 13930 0 15041
COGNEX CORP COMMON 192422103 6885 290665 290665 217265 0 73400
COLGATE PALMOLIVE CO COMMON 194162103 736 8000 8000 0 0 8000
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 6
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
COMCAST CORP - CL A COMMON 200300101 5016 81555 81555 75955 0 5600
COMCAST CORP - SP A COMMON 200300200 940 29860 29860 25260 0 4600
COMMSCOPE INC COMMON 203372107 19980 954245 954245 778340 0 175905
COMVERSE TECHNOLOGY INC COMMON 205862402 2151 25300 25300 25050 0 250
CONCENTRIC NETWORK CORP COMMON 20589R107 6168 82516 82516 74300 0 8216
CONCORD COMMUNICATIONS I COMMON 206186108 14733 258475 258475 218600 0 39875
CONCUR TECHNOLOGIES INC COMMON 206708109 1568 34750 34750 20025 0 14725
COORS ADOLPH CO COMMON 217016104 301 5580 5580 5530 0 50
CORINTHIAN COLLEGES INC COMMON 218868107 4034 183380 183380 148880 0 34500
CORNING INC COMMON 219350105 1827 30450 30450 20400 0 10050
CORPORATE EXECUTIVE BRD COMMON 21988R102 535 20300 20300 14010 0 6290
COSTCO COMPANIES INC COMMON 22160Q102 16747 182898 182898 117380 0 65518
COVAD COMMUNICATIONS GRO COMMON 222814204 59818 909785 909785 750660 0 159125
COX COMMUNICATIONS INC COMMON 224044107 3393 44870 44870 34670 0 10200
CRITICAL PATH INC COMMON 22674V100 4250 55200 55200 35700 0 19500
CYTYC CORP COMMON 232946103 2163 155900 155900 142700 0 13200
DELIA*S INC COMMON 246885107 1508 47875 47875 31800 0 16075
DESCARTES SYS GROUP INC COMMON 249906108 2397 311830 311830 193700 0 118130
DEUTSCHE TELEKOM AG COMMON 251566105 2743 67835 67835 63585 0 4250
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 7
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
DIAMOND OFFSHORE DRILLIN COMMON 25271C102 2832 89555 89555 88655 0 900
DIGITAL RIV INC COMMON 25388B104 6223 155580 155580 105020 0 50560
DIGITAL LAVA INC COMMON 253928105 563 50000 50000 50000 0 0
DIGITAL LAVA INC COMMON 253928105 281 25000 25000 25000 0 0
DOLLAR TREE STORES INC COMMON 256747106 12970 419222 419222 371652 0 47570
DONALDSON LUFKIN & JENRE COMMON 257661108 4338 62200 62200 55800 0 6400
DOUBLECLICK INC COMMON 258609304 28223 155018 155018 130637 0 24381
DREXLER TECHNOLOGY CORP COMMON 261876106 440 45100 45100 45100 0 0
DU PONT E I DE NEMOURS & COMMON 263534109 613 10562 10562 700 0 9862
DUKE ENERGY CORP COMMON 264399106 278 5075 5075 208 0 4867
DYCOM INDS INC COMMON 267475101 740 17000 17000 17000 0 0
E M C CORP MASS COMMON 268648102 67005 524500 524500 495750 0 28750
ENSCO INTL INC COMMON 26874Q100 6478 486600 486600 444900 0 41700
ESAT TELECOM GROUP PLC COMMON 26883Y102 1433 34230 34230 21865 0 12365
E-TEK DYNAMICS INC COMMON 269240107 2045 57000 57000 35000 0 22000
EARTHLINK NETWORK INC COMMON 270322100 26151 435850 435850 368125 0 67725
EBAY INC COMMON 278642103 23875 173873 173873 146483 0 27390
EDUCATION MGMT CORP COMMON 28139T101 9103 296030 296030 218230 0 77800
ELAN PLC COMMON 284131208 268 3848 3848 1975 0 1873
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 8
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
ELECTRONICS FOR IMAGING COMMON 286082102 620 15900 15900 15900 0 0
ENERGIS PLC ADR COMMON 29266H100 4529 33800 33800 22375 0 11425
ENRON CORP COMMON 293561106 488 7600 7600 1200 0 6400
ENTERCOM COMMUNICATIONS COMMON 293639100 1907 53900 53900 32100 0 21800
EQUANT N V COMMON 294409107 64818 861370 861370 675400 0 185970
EQUITY OFFICE PROPERTIES COMMON 294741103 406 16000 16000 7200 0 8800
EVEREST REINS HLDGS INC COMMON 299808105 730 23400 23400 16800 0 6600
EXCEL SWITCHING CORP COMMON 30067V108 2337 111300 111300 93600 0 17700
EXCHANGE APPLICATIONS COMMON 300867108 756 30100 30100 24700 0 5400
EXODUS COMMUNICATIONS IN COMMON 302088109 23607 175515 175515 142865 0 32650
EXPRESS SCRIPTS INC COMMON 302182100 11033 128385 128385 102385 0 26000
EXXON CORP COMMON 302290101 1971 27934 27934 15534 0 12400
FATBRAIN COM INC COMMON 311889109 1381 60370 60370 57870 0 2500
ESSEX HIGH TECH FUND LP COMMON 313999104 6638 943 943 763 0 180
ESSEX PERFORMANCE FUND COMMON 330995101 2185 110053 110053 0 0 110053
FIRST UN CORP COMMON 337358105 2396 44830 44830 44830 0 0
FIRST YRS INC COMMON 337610109 223 16000 16000 16000 0 0
FLEXPORT MID CAP COMMON 339994105 1063 390000 390000 0 0 390000
FLEXPORT LARGE CAP COMMON 339996100 1720 650000 650000 0 0 650000
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COLUMN TOTALS
</TABLE>
<PAGE>
Page 9
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
FOREST LABS INC COMMON 345838106 35676 632830 632830 584165 0 48665
FOX ENTMT GROUP INC COMMON 35138T107 6784 250100 250100 250100 0 0
FRANCE TELECOM COMMON 35177Q105 387 4800 4800 3000 0 1800
FRONTIER CORP COMMON 35906P105 311 6000 6000 0 0 6000
GTE CORP COMMON 362320103 330 5450 5450 4825 0 625
GANNETT INC COMMON 364730101 687 10900 10900 10900 0 0
GARDEN FRESH RESTAURANT COMMON 365235100 1799 126220 126220 93770 0 32450
GELTEX PHARMACEUTICALS COMMON 368538104 4112 292438 292438 195258 0 97180
GENENTECH INC COMMON 368710307 222 2500 2500 0 0 2500
GENERAL ELEC CO COMMON 369604103 10345 93511 93511 71001 0 22510
GENERAL MTRS CORP COMMON 370442105 285 3280 3280 3280 0 0
GENESYS TELECOMMUNICATIO COMMON 371931106 767 50890 50890 17290 0 33600
GEOCITIES COMMON 37247V106 32656 298055 298055 210560 0 87495
GENZYME CORP GENL DIV COMMON 372917104 3775 74840 74840 46740 0 28100
GEOTEL COMMUNICATIONS CO COMMON 373656107 33308 726050 726050 626915 0 99135
GILEAD SCIENCES INC COMMON 375558103 9066 199250 199250 190350 0 8900
GILLETTE CO COMMON 375766102 2778 46745 46745 32190 0 14555
GLENBOROUGH RLTY TR INC COMMON 37803P105 464 27300 27300 9800 0 17500
GLOBAL TELESYSTEMS GROUP COMMON 37936U104 76144 1361230 1361230 1120960 0 240270
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 10
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
GOLF TR AMER INC COMMON 38168B103 846 37810 37810 23950 0 13860
GO2NET INC COMMON 383486107 4237 31950 31950 25650 0 6300
GREAT PLAINS SOFTWARE COMMON 39119E105 39851 1030083 1030083 775883 0 254200
GUIDANT CORP COMMON 401698105 3677 60780 60780 37590 0 23190
HALLIBURTON CO COMMON 406216101 24857 645630 645630 576345 0 69285
HAMBRECHT & QUIST GRP COMMON 406545103 12421 358087 358087 224882 0 133205
HANDLEMAN CO DEL COMMON 410252100 4053 303050 303050 273050 0 30000
HANGER ORTHOPEDIC GROUP COMMON 41043F208 473 35050 35050 30850 0 4200
HARMON INDS INC NEW COMMON 413136102 6228 310450 310450 310450 0 0
HARRAHS ENTMT INC COMMON 413619107 722 37900 37900 37900 0 0
HARTFORD FINL SVCS GROUP COMMON 416515104 5386 94800 94800 83800 0 11000
CANAL PLUS COMMON 4171720 498 1700 1700 1700 0 0
HEALTHSOUTH CORP COMMON 421924101 2005 193281 193281 171981 0 21300
HELIX TECHNOLOGY CORP COMMON 423319102 1455 94615 94615 69665 0 24950
HEWLETT PACKARD CO COMMON 428236103 13240 195251 195251 140471 0 54780
HI / FN INC COMMON 428358105 1054 28100 28100 27600 0 500
HOLLYWOOD ENTMT CORP COMMON 436141105 1337 71800 71800 62300 0 9500
HOME DEPOT INC COMMON 437076102 66279 1064718 1064718 858996 0 205722
HONG KONG TELECOMMUNICAT COMMON 438579203 1035 52900 52900 52900 0 0
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 11
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
HOUSEHOLD INTL INC COMMON 441815107 237 5187 5187 5187 0 0
IMS HEALTH INC COMMON 449934108 22302 673280 673280 500260 0 173020
IRT CORP COMMON 450052303 4 15893 15893 0 0 15893
ISS GROUP INC COMMON 450306105 3287 41350 41350 10300 0 31050
ITT EDUCATIONAL SERVICES COMMON 45068B109 13293 353890 353890 305915 0 47975
IMMUNEX CORP NEW COMMON 452528102 583 7000 7000 5000 0 2000
INCO LTD COMMON 453258402 160 12000 12000 2000 0 10000
INFINITY BROADCASTING CP COMMON 45662S102 8145 316300 316300 269200 0 47100
INFOSEEK CORP COMMON 45678M107 5293 71525 71525 61040 0 10485
INFOSPACE COM INC COMMON 45678T102 59596 672450 672450 550155 0 122295
INKTOMI CORP COMMON 457277101 8656 100950 100950 100950 0 0
INPUT/OUTPUT INC COMMON 457652105 1578 250000 250000 250000 0 0
INSITUFORM TECHNOLS COMMON 457667103 1817 103830 103830 103830 0 0
INNKEEPERS USA TR COMMON 4576J0104 276 29650 29650 13000 0 16650
INTEL CORP COMMON 458140100 16377 137765 137765 110135 0 27630
INTERNATIONAL BUS MACH COMMON 459200101 2062 11633 11633 11033 0 600
INTERNATIONAL TELECOMMUN COMMON 46047F104 3173 256400 256400 225400 0 31000
INTERPUBLIC GROUP COS IN COMMON 460690100 911 11700 11700 5900 0 5800
INTRAWARE INC COMMON 46118M103 389 9705 9705 7570 0 2135
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 12
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
INTUIT COMMON 461202103 54577 536380 536380 428510 0 107870
INVESTMENT TECHNOLOGY GR COMMON 46145F105 0 15300 15300 9500 0 5800
INVITROGEN CORP COMMON 46185R100 11664 905960 905960 714430 0 191530
IOMEGA CORP COMMON 462030107 750 146275 146275 105775 0 40500
IONICS INC COMMON 462218108 753 25000 25000 25000 0 0
I2 TECHNOLOGIES INC COMMON 465754109 19526 734245 734245 603070 0 131175
JDS FITEL INC COMMON 465934107 4434 78920 78920 36000 0 42920
JAMESON INNS INC COMMON 470457102 246 27150 27150 1150 0 26000
JEFFERIES GROUP INC NEW COMMON 472319102 0 15300 15300 9500 0 5800
JOHN NUVEEN CO COMMON 478035108 209 5000 5000 5000 0 0
JOHNSON & JOHNSON COMMON 478160104 3286 35148 35148 2640 0 32508
JONES INTERCABLE INC COMMON 480206200 9373 237675 237675 213800 0 23875
KLA-TENCOR CORP COMMON 482480100 287 5900 5900 5900 0 0
KEYCORP NEW COMMON 493267108 546 18000 18000 0 0 18000
KIMBERLY CLARK CORP COMMON 494368103 384 8000 8000 0 0 8000
KINDER MORGAN ENERGY PAR COMMON 494550106 481 13900 13900 13900 0 0
KING PHARMACEUTICALS INC COMMON 495582108 37375 1346850 1346850 1118940 0 227910
KNIGHT/TRIMARK GROUP INC COMMON 499067106 98591 1471500 1471500 1181910 0 289590
KONINKLIJKE PHILIPS ELEC COMMON 500472105 1970 23900 23900 21000 0 2900
KROGER CO COMMON 501044101 597 9975 9975 9175 0 800
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 13
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
KROLL O GARA CO COMMON 501050108 1928 71070 71070 48470 0 22600
KRONOS INC COMMON 501052104 4824 196882 196882 192982 0 3900
LSI LOGIC CORP COMMON 502161102 2065 66225 66225 42900 0 23325
LABOR READY INC COMMON 505401208 907 34700 34700 12100 0 22600
LASER VISION CTRS INC COMMON 51807H100 6269 164425 164425 133325 0 31100
LASON INC COMMON 51808R107 14507 257895 257895 204795 0 53100
LAUDER ESTEE COS INC COMMON 518439104 229 2420 2420 1170 0 1250
LEARNING COMPANY INC COMMON 522008101 363 12500 12500 2500 0 10000
LEGATO SYSTEMS INC COMMON 524651106 2447 47400 47400 0 0 47400
LEVEL 3 COMMUNICATIONS I COMMON 52729N100 2752 37800 37800 33400 0 4400
LEXMARK INTL GROUP INC COMMON 529771107 38188 341345 341345 242120 0 99225
LILLY ELI & CO COMMON 532457108 6940 81771 81771 55371 0 26400
LINENS N THINGS INC COMMON 535679104 22631 498755 498755 368420 0 130335
LOWES COS INC COMMON 548661107 957 15815 15815 12325 0 3490
LUCENT TECHNOLOGIES INC COMMON 549463107 3268 30262 30262 24399 0 5863
LYCOS INC COMMON 550818108 7095 82439 82439 69194 0 13245
MCI WORLDCOM INC COMMON 55268B106 115481 1303948 1303948 985572 0 318376
MDSI MOBILE DATA SOLUTIO COMMON 55268N100 5082 344532 344532 278732 0 65800
MGM GRAND INC COMMON 552953101 605 18000 18000 18000 0 0
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 14
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
MKS INSTRUMENT INC COMMON 55306N104 2666 199300 199300 171400 0 27900
MPSI SYSTEMS (UNRESTR) COMMON 553412206 44 20500 20500 0 0 20500
MACROVISION CORP COMMON 555904101 5587 151000 151000 141300 0 9700
MACROMEDIA INC COMMON 556100105 2995 66100 66100 66100 0 0
MARINE DRILLING COS INC COMMON 568240204 1302 118350 118350 104000 0 14350
MARSH & MCLENNAN COS INC COMMON 571748102 5157 69450 69450 61150 0 8300
MATHSOFT INC COMMON 576798102 64 20000 20000 0 0 20000
LOOKSMART, LTD SER C PFD COMMON 576990105 1500 200000 200000 0 0 200000
MAXIMUS INC COMMON 577933104 232 7950 7950 6750 0 1200
MCCORMICK & CO INC COMMON 579780206 502 17325 17325 11925 0 5400
MCDERMOTT INTL INC COMMON 580037109 1233 48700 48700 47700 0 1000
MCDONALDS CORP COMMON 580135101 544 12000 12000 980 0 11020
MCGRAW HILL COS INC COMMON 580645109 64437 1182330 1182330 973100 0 209230
MEDIAONE GROUP INC COMMON 58440J104 39261 618893 618893 540070 0 78823
MEDIAONE GROUP INC PFD CV 58440J203 290 2256 2256 0 0 2256
MEDIALINK WORLDWIDE INC COMMON 58445P105 408 32300 32300 25500 0 6800
MEDIMMUNE INC COMMON 584699102 811 13700 13700 13700 0 0
MEDQUIST INC COMMON 584949101 9511 317045 317045 227695 0 89350
MEDTRONIC INC COMMON 585055106 32242 448585 448585 388500 0 60085
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 15
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
MENTOR GRAPHICS CORP COMMON 587200106 1882 139375 139375 107600 0 31775
MERCK & CO INC COMMON 589331107 3047 38030 38030 7730 0 30300
MERCURY COMPUTER SYS COMMON 589378108 6201 344495 344495 271595 0 72900
MERRILL LYNCH & CO INC COMMON 590188108 4712 53245 53245 52320 0 925
METROMEDIA FIBER NETWORK COMMON 591689104 19748 381140 381140 323465 0 57675
METZLER GROUP INC COMMON 592903108 22448 715474 715474 588224 0 127250
MEYER FRED INC COMMON 592907109 294 4990 4990 3990 0 1000
MICROSOFT CORP COMMON 594918104 124179 1385540 1385540 1107040 0 278500
MICROMUSE INC COMMON 595094103 72832 1583300 1583300 1286610 0 296690
MICRON TECHNOLOGY INC COMMON 595112103 1359 28200 28200 24900 0 3300
MILLENNIUM PHARMACEUTICA COMMON 599902103 9239 295633 295633 210493 0 85140
MINDSPRING ENTERPRISES COMMON 602683104 5132 59635 59635 46435 0 13200
MINNESOTA MNG & MFG CO COMMON 604059105 299 4224 4224 470 0 3754
MIRAGE RESORTS INC COMMON 60462E104 731 34400 34400 34400 0 0
MOBIUS MGMT SYSTEMS INC COMMON 606925105 510 24300 24300 24100 0 200
MOBIL CORP COMMON 607059102 840 9546 9546 1900 0 7646
MODEM MEDIA POPPE TYSON COMMON 607533106 695 16200 16200 13300 0 2900
MONSANTO CO COMMON 611662107 53880 1172900 1172900 1016900 0 156000
MONTANA POWER COMPANY COMMON 612085100 41128 559095 559095 388310 0 170785
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 16
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
MOTOROLA INC/CV/LYON BND CV 620076AE9 336 250000 250000 250000 0 0
MUTUAL RISK MGMT LTD COMMON 628351108 670 17410 17410 10100 0 7310
NCO GROUP INC COMMON 628858102 9690 261900 261900 224600 0 37300
NTL INC COMMON 629407107 1636 20100 20100 20100 0 0
NATIONAL COMPUTER SYS IN COMMON 635519101 10384 423845 423845 354545 0 69300
NATIONAL GOLF PPTYS INC COMMON 63623G109 299 13600 13600 500 0 13100
NATIONWIDE FINL SVCS COMMON 638612101 214 5100 5100 5100 0 0
NEFF CORP COMMON 640094108 2566 320760 320760 209760 0 111000
NETBANK INC COMMON 640933107 532 7825 7825 7780 0 45
NETGRAVITY INC COMMON 641114103 46928 1134200 1134200 972435 0 161765
NETWORK APPLIANCE INC COMMON 64120L104 33225 656295 656295 553015 0 103280
NETWORK SOLUTIONS INC DE COMMON 64121Q102 34618 327360 327360 260720 0 66640
NEW ERA OF NETWORKS INC COMMON 644312100 42880 632915 632915 522150 0 110765
NEWPARK RES INC COMMON 651718504 725 100000 100000 100000 0 0
NEXTLINK COMMUNICATNS COMMON 65333H707 9144 163285 163285 109620 0 53665
NICOR INC COMMON 654086107 359 10000 10000 10000 0 0
NIPPON TELEG & TEL CORP COMMON 654624105 1219 25000 25000 25000 0 0
NOBLE AFFILIATES INC COMMON 654894104 12604 434630 434630 294135 0 140495
NOKIA CORP COMMON 654902204 20227 129870 129870 99485 0 30385
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 17
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
NOBLE DRILLING CORP COMMON 655042109 14272 821420 821420 646520 0 174900
NORTEL NETWORKS CORP COMMON 656569100 476 7667 7667 0 0 7667
NORTHERN TR CORP COMMON 665859104 603 6788 6788 1000 0 5788
NVIDIA CORP COMMON 67066G104 215 10175 10175 5175 0 5000
OFFICEMAX INC COMMON 67622M108 86 10000 10000 0 0 10000
SOFTBANK CORP COMMON 6770620 19824 176800 176800 124700 0 52100
OMNICOM GROUP INC COMMON 681919106 743 9300 9300 8100 0 1200
ONEMAIN COM INC COMMON 68267P109 988 27264 27264 20239 0 7025
ONYX SOFTWARE CORP COMMON 683402101 661 16900 16900 10500 0 6400
OPEN MKT INC COMMON 68370M100 509 39355 39355 0 0 39355
OPTICAL COATING LAB INC COMMON 683829105 3850 80200 80200 80200 0 0
ORACLE CORP COMMON 68389X105 532 20185 20185 12505 0 7680
O'REILLY AUTOMOTIVE COMMON 686091109 10047 224525 224525 181625 0 42900
OSTEOTECH INC COMMON 688582105 10681 310725 310725 229389 0 81336
TOSHIBA CORPORATION COMMON 6897217 1011 148000 148000 96500 0 51500
OUTBACK STEAKHOUSE INC COMMON 689899102 48249 1473238 1473238 1165876 0 307362
OWENS-ILLINOIS INC COMMON 690768403 2175 87000 87000 77300 0 9700
P F CHANGS CHINA BISTRO COMMON 69333Y108 13464 441445 441445 342195 0 99250
PARAMETRIC TECHNOLOGY CO COMMON 699173100 9017 456580 456580 405875 0 50705
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 18
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
PAREXEL INTL CORP COMMON 699462107 3394 164040 164040 150340 0 13700
PAYMENTECH INC COMMON 704384106 3021 127875 127875 117975 0 9900
PEGASUS SYSTEMS INC COMMON 705906105 339 8500 8500 7500 0 1000
PEOPLESOFT INC COMMON 712713106 284 19400 19400 19400 0 0
PEPSICO INC COMMON 713448108 314 8017 8017 2750 0 5267
PEREGRINE SYSTEMS INC COMMON 71366Q101 11370 338130 338130 267255 0 70875
PERITUS SOFTWARE SVC COMMON 714006103 15 68904 68904 0 0 68904
PERKIN ELMER CORP COMMON 714041100 18963 195365 195365 163110 0 32255
PEROT SYS CORP COMMON 714265105 3019 117820 117820 79020 0 38800
PETROLEUM GEO-SVCS A/S COMMON 716597109 23719 1555320 1555320 1288420 0 266900
PFIZER INC COMMON 717081103 42161 303865 303865 206675 0 97190
PINNACLE SYS INC COMMON 723481107 3868 85000 85000 75000 0 10000
PIXAR INC COMMON 725811103 2008 51000 51000 50000 0 1000
POLAROID CORP COMMON 731095105 7288 361030 361030 322945 0 38085
POLICY MGMT SYS CORP COMMON 731108106 2612 85280 85280 39430 0 45850
POLYCOM INC COMMON 73172K104 16909 901815 901815 756115 0 145700
PRENTISS PPTYS TR COMMON 740706106 405 21575 21575 7950 0 13625
PREVIEW TRAVEL INC COMMON 74137R101 950 50000 50000 50000 0 0
PRICELINE COM INC COMMON 741503106 69732 841410 841410 565015 0 276395
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 19
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
PROBUSINESS SERVICES INC COMMON 742674104 15347 365395 365395 275440 0 89955
PROCTER & GAMBLE CO COMMON 742718109 1456 14864 14864 40 0 14824
PROFIT RECOVERY GROUP IN COMMON 743168106 4369 110600 110600 110600 0 0
PROGRESSIVE CORP OHIO COMMON 743315103 5373 37440 37440 33140 0 4300
PROVANT INC COMMON 743724106 3306 184970 184970 173970 0 11000
DYAX CORP PFD CV 743997892 103 28944 28944 28944 0 0
PROXIM INC COMMON 744284100 739 25700 25700 25700 0 0
QLT PHOTOTHERAPEUTICS IN COMMON 746927102 10400 255225 255225 230225 0 25000
QRS CORP COMMON 74726X105 2208 35300 35300 25200 0 10100
QLOGIC CORP COMMON 747277101 11886 177075 177075 129110 0 47965
QUALCOMM INC COMMON 747525103 5432 43675 43675 38175 0 5500
QUINTILES TRANSNATIONAL COMMON 748767100 4932 130645 130645 105120 0 25525
QWEST COMMUNICATIONS INT COMMON 749121109 163545 2268505 2268505 1823705 0 444800
RCN CORP COMMON 749361101 53894 1605769 1605769 1263713 0 342056
RF MICRODEVICES INC COMMON 749941100 3024 31600 31600 31600 0 0
RANGER OIL LTD COMMON 752805101 51 12700 12700 1000 0 11700
RATIONAL SOFTWARE CORP COMMON 75409P202 14463 539430 539430 432730 0 106700
READERS DIGEST CLASS A COMMON 755267101 409 13000 13000 12500 0 500
REINSURANCE GROUP AMER I COMMON 759351208 407 12000 12000 12000 0 0
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 20
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
RESEARCH IN MOTION LTD COMMON 760975102 654 62300 62300 40500 0 21800
RESOLUTION TECH INC COMMON 761990100 0 250000 250000 200000 0 50000
ROGERS CANTEL MOBILE COM COMMON 775102205 1355 75000 75000 75000 0 0
ROYAL DUTCH PETE CO COMMON 780257804 1238 23812 23812 5561 0 18251
SBC COMMUNICATIONS INC COMMON 78387G103 1641 34786 34786 4050 0 30736
SAFEGUARD SCIENTIFICS IN COMMON 786449108 15692 232475 232475 171350 0 61125
SAFEWAY INC COMMON 786514208 6423 125165 125165 83155 0 42010
SANDISK INC COMMON 80004C101 1830 69050 69050 64250 0 4800
SBS BROADCASTING SA BND CV 805906AB0 479 390000 390000 390000 0 0
SCHERING PLOUGH CORP COMMON 806605101 10686 193420 193420 123480 0 69940
SCHLUMBERGER LTD COMMON 806857108 69565 1155800 1155800 981855 0 173945
SCHOOL SPECIALTY INC COMMON 807863105 9230 471825 471825 351805 0 120020
SEAGRAM LTD COMMON 811850106 6638 132760 132760 111100 0 21660
SEPRACOR INC COMMON 817315104 82953 739000 739000 624950 0 114050
SEROLOGICALS CORP COMMON 817523103 12339 909769 909769 772918 0 136851
SILVERSTREAM SER D PFD COMMON 828990101 3250 342105 342105 57530 0 284575
SILVERSTREAM SOFTWARE COMMON 828995100 4328 455581 455581 455581 0 0
SNYDER COMMUNICATIONS IN COMMON 832914105 1475 52900 52900 48700 0 4200
SOFTECH INC COMMON 834021107 78 31000 31000 0 0 31000
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 21
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
SONY CORP COMMON 835699307 72476 793715 793715 668405 0 125310
SPRINT CORP FON GROUP COMMON 852061100 8687 88535 88535 69645 0 18890
SPRINT CORP FON GROUP COMMON 852061506 3571 80593 80593 64870 0 15723
SPYGLASS INC COMMON 852192103 274 30400 30400 22100 0 8300
STAPLES INC COMMON 855030102 86561 2633025 2633025 2195164 0 437861
STARBUCKS CORP COMMON 855244109 3159 112562 112562 51010 0 61552
STATE STR CORP COMMON 857477103 7012 85249 85249 75915 0 9334
STERIS CORP COMMON 859152100 6968 261700 261700 251700 0 10000
STERIGENICS INTL INC COMMON 85915R105 4512 462745 462745 307295 0 155450
STMICROELECTRONICS N V COMMON 861012102 209 2150 2150 0 0 2150
SUN MICROSYSTEMS INC COMMON 866810104 1338 10700 10700 5300 0 5400
SUNGARD DATA SYS INC COMMON 867363103 266 6656 6656 0 0 6656
SUNRISE ASSISTED LIVNG COMMON 86768K106 2495 54750 54750 50550 0 4200
SUPERIOR CONSULTANT HLDG COMMON 868146101 8464 248025 248025 210725 0 37300
SYMBOL TECHNOLOGIES COMMON 871508107 11692 259813 259813 228813 0 31000
SYNOPSYS INC COMMON 871607107 11731 218250 218250 180300 0 37950
TJX COS INC NEW COMMON 872540109 1774 52180 52180 31830 0 20350
TSI INTERNATIONAL SOFTWA COMMON 872879101 6375 130600 130600 102525 0 28075
TLC THE LASER CTR INC COMMON 872934104 13911 432195 432195 357695 0 74500
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 22
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
TMP WORLDWIDE INC COMMON 872941109 2813 43400 43400 41300 0 2100
TAIWAN SEMICONDCTR MFG COMMON 874039100 631 26700 26700 26700 0 0
TELEBANC FINANCIAL CORP COMMON 87925R109 42800 536680 536680 372580 0 164100
TELECOMUNICACOES BRASILE COMMON 879287308 12045 149400 149400 132800 0 16600
TELEFONOS DE MEXICO SA COMMON 879403780 330 5000 5000 0 0 5000
TELTONE CORP COMMON 87969L109 4 10676 10676 0 0 10676
TELESYSTEM INTL WIRELESS COMMON 879946101 14862 855390 855390 608480 0 246910
TERADYNE INC COMMON 880770102 48064 880898 880898 743355 0 137543
TEXACO INC COMMON 881694103 301 5300 5300 500 0 4800
TEXAS INSTRS INC COMMON 882508104 9166 92350 92350 73460 0 18890
TICKETMASTER ONLINE-CITY COMMON 88633P203 2922 86900 86900 69000 0 17900
TIME WARNER INC COMMON 887315109 33637 475015 475015 366510 0 108505
TIMES MIRROR CO NEW COMMON 887364107 767 14165 14165 6790 0 7375
TOSCO CORP COMMON 891490302 215 8650 8650 8650 0 0
TRAVELERS PPTY CAS CORP COMMON 893939108 2553 71400 71400 63400 0 8000
TRIBUNE CO NEW COMMON 896047107 988 15100 15100 15100 0 0
TUT SYSTEMS COMMON 901103101 2642 53100 53100 51700 0 1400
TWEETER HOME ENTMT GROUP COMMON 901167106 17655 547455 547455 477520 0 69935
TYCO INTL LTD NEW COMMON 902124106 8649 120550 120550 106050 0 14500
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 23
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
USA NETWORKS INC COMMON 902984103 1474 41150 41150 32700 0 8450
ULTRAMAR DIAMOND SHAMROC COMMON 904000106 285 13200 13200 13200 0 0
UNIPHASE CORP COMMON 909149106 116135 1008775 1008775 829995 0 178780
UNITED INTL HLDGS INC COMMON 910734102 5574 128140 128140 103040 0 25100
UNITED PAN-EUROPE COMMUN COMMON 911300200 22427 586320 586320 482720 0 103600
UNITED TECHNOLOGIES CORP COMMON 913017109 655 4837 4837 4362 0 475
UNIVISION COMMUNICATIONS COMMON 914906102 297 5935 5935 3335 0 2600
USWEB CORP COMMON 917327108 19861 481480 481480 384030 0 97450
VARCO INTL INC COMMON 922126107 14025 1260700 1260700 999400 0 261300
VASTAR RESOURCES LTD COMMON 922380100 9314 195065 195065 121695 0 73370
VERITAS SOFTWARE CO COMMON 923436109 59314 734539 734539 660859 0 73680
VERISIGN INC COMMON 92343E102 95535 620360 620360 470835 0 149525
VERISITY LTD SER D PFD COMMON 923991103 500 67884 67884 0 0 67884
VERTICALNET INC COMMON 92532L107 52642 506785 506785 375595 0 131190
VIACOM INC/CL B COMMON 925524308 9234 110015 110015 73115 0 36900
VIATEL INC COMMON 925529208 618 21700 21700 21700 0 0
VIGNETTE CORP COMMON 926734104 8463 112460 112460 92860 0 19600
VISIBLE GENETICS INC COMMON 92829S104 2208 126165 126165 126165 0 0
VISUAL NETWORKS INC COMMON 928444108 1148 30723 30723 30723 0 0
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 24
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
VISX INC DEL COMMON 92844S105 50404 468600 468600 372190 0 96410
VITESSE SEMICONDUCTOR CO COMMON 928497106 6779 133900 133900 127125 0 6775
WAL MART STORES INC COMMON 931142103 55883 606186 606186 539380 0 66806
WALGREEN CO COMMON 931422109 6119 216600 216600 151860 0 64740
WARNER LAMBERT CO COMMON 934488107 11764 177565 177565 131425 0 46140
WASTE MGMT INC DEL COMMON 94106L109 487 10985 10985 5508 0 5477
WATERS CORP COMMON 941848103 31990 304485 304485 267035 0 37450
WATSON PHARMACEUTICALS I COMMON 942683103 524 11885 11885 9885 0 2000
WEATHERFORD INTL INC COMMON 947074100 705 27000 27000 25000 0 2000
WEBTRENDS CORP COMMON 94844D104 778 16000 16000 14200 0 1800
WEEKS CORP COMMON 94856P102 223 7800 7800 4300 0 3500
WELLS FARGO & CO NEW COMMON 949746101 231 6600 6600 6600 0 0
WESTERN WIRELESS CORP COMMON 95988E204 1260 34750 34750 22800 0 11950
WILLIAMS COS INC DEL COMMON 969457100 112054 2836802 2836802 2296647 0 540155
WINSTAR COMMUNICATIONS COMMON 975515107 57840 1591475 1591475 1212735 0 378740
WOMEN.COM NETWORKS COMMON 978990109 600 182370 182370 148020 0 34350
XILINX INC COMMON 983919101 3214 79225 79225 51100 0 28125
XEROX CORP COMMON 984121103 557 10684 10684 5284 0 5400
XOOM COM INC COMMON 98413F101 5316 79275 79275 72075 0 7200
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
</TABLE>
<PAGE>
Page 25
<TABLE>
<CAPTION>
FORM 13F
REPORTING MANAGER; ESSEX INVESTMENT MGMT CO
- ------------------------------------------------------------------------------------------------------------------------------------
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 CLASS NUMBER MARKET PRINCIPAL SHARED GERS
VALUE AMOUNT SOLE SHARED OTHER SOLE SHARED NONE
(A) (B) (C) (A) (B) (C)
- ------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
YAHOO INC COMMON 984332106 117575 698293 698293 536338 0 161955
YOUNG & RUBICAM INC COMMON 987425105 5888 144500 144500 144000 0 500
ZIFF-DAVIS INC COMMON 989511209 2052 57000 57000 36010 0 20990
ZONAGEN INC COMMON 98975L108 2813 130850 130850 99450 0 31400
DAIMLERCHRYSLER AG COMMON D1668R123 293 3420 3420 1920 0 1500
ACE LTD COMMON G0070K103 4385 140600 140600 123700 0 16900
AMDOCS LTD COMMON G02602103 71365 3300100 3300100 2759430 0 540670
GEMSTAR INTL GROUP LTD COMMON G3788V106 34604 459855 459855 365025 0 94830
GLOBAL CROSSING LTD COMMON G3921A100 40930 884970 884970 720630 0 164340
RENAISSANCE RE HLDGS LTD COMMON G7496G103 335 9600 9600 5250 0 4350
RSL COMMUNICATIONS LTD COMMON G7702U102 59609 1658680 1658680 1348480 0 310200
SANTA FE INTL CORP COMMON G7805C108 17921 958960 958960 777460 0 181500
XL CAP LTD COMMON G98255105 3900 64200 64200 54800 0 9400
ASM LITHOGRAPHY HLDG N V COMMON N07059111 5739 127525 127525 101000 0 26525
CORE LABORATORIES N V COMMON N22717107 4540 257600 257600 244900 0 12700
ROYAL CARIBBEAN CRUISE COMMON V7780T103 8658 222000 222000 222000 0 0
PACIFIC INTERNET LTD COMMON Y66183107 477 8200 8200 6000 0 2200
------ ------- ------- ------ ------ -------- ------- ------
COLUMN TOTALS
------ ------- ------- ------ ------ -------- ------- ------
REPORT TOTALS
====== ======= ======= ====== ====== ======== ======= ======
</TABLE>
