<PAGE>
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form 13F
Form 13F COVER PAGE
Report for the Calendar Year or Quarter Ended: March 31, 2000
Check here if Amendment [ ]; Amendment Number:
-----------------------
This Amendment (Check only one): [ ] is a restatement.
[ ] adds new holdings
entries.
Institutional Investment Manager Filing this Report:
Name: Oberweis Asset Management, Inc.
Address: 951 Ice Cream Dr., Suite 200
North Aurora, IL 60542
Form 13F File Number: 28-4688
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: Patrick B. Joyce
Title: Executive Vice President
Phone: (800) 323-6166
Signature, Place, and Date of Signing:
Patrick B. Joyce North Aurora, IL May 10, 2000
- ----------------
[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 manger are reported in this report and a portion are reported by other
reporting manager(s).)
<PAGE>
Oberweis Asset Management, Inc.
FORM 13F
March 31, 2000
<TABLE>
<CAPTION>
Voting Authority
Value Shares/ Sh/ Put/ Invstmt Other ------------------------
Name of Issuer Title of Class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers Sole Shared None
- ------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
1-800 Contacts, Inc. com 681977104 1073 31000 SH Sole 30000 1000
4Front Technologies, Inc. com 351042106 270 13000 SH Sole 13000
ACT Manufacturing Inc. com 000973107 1001 17900 SH Sole 15000 2900
ATMI,Inc. com 00207R101 3925 82205 SH Sole 70000 12205
AVT Corporation com 002420107 217 18400 SH Sole 18400
Abaxis com 002567105 209 25000 SH Sole 25000
Act Teleconferencing, Inc. com 126 10000 SH Sole 10000
Acxiom Corp. com 005125109 456 13700 SH Sole 13700
Administaff, Inc. com 392 10000 SH Sole 10000
Advance Paradigm Inc. com 007491103 3204 269800 SH Sole 230000 39800
Advanced Digital com 007525108 514 15000 SH Sole 15000
Akorn, Inc. com 009728106 284 29900 SH Sole 29900
Amdocs LTD. com g02602103 368 5000 SH Sole 5000
American Eagle Outfitters com 02553E106 3384 89200 SH Sole 75000 14200
American Management Systems com 027352103 307 7000 SH Sole 7000
Anadigics, Inc. com 032515108 267 4050 SH Sole 3000 1050
Andrx Corporation com 034551101 11475 99350 SH Sole 82500 16850
Applied Power, Inc.-CL A com 038225108 231 8100 SH Sole 8100
Aremissoft Corporation com 040026106 1353 39800 SH Sole 10000 29800
Arguss Holdings com 224 10000 SH Sole 10000
Aspeon, Inc. com 045354107 5834 288100 SH Sole 259500 28600
Atwood Oceanics, Inc. com 050095108 484 7300 SH Sole 7300
Audiovox Corporation Class A com 050757103 6411 146950 SH Sole 116000 30950
Avanti Corporation com 053487104 150 12000 SH Sole 12000
Avert, Inc. com 053596102 1380 46000 SH Sole 30000 16000
Barr Labs com 068306109 244 5800 SH Sole 5800
Barrett Resources Corporation com 068480201 1395 46800 SH Sole 45000 1800
Bell Microproducts com 078137106 457 26500 SH Sole 20000 6500
Beta Oil & Gas, Inc. com 08659A104 331 33500 SH Sole 20000 13500
Brooktrout Technology com 114580103 870 30000 SH Sole 30000
Business Resource Group com 12329k104 317 40000 SH Sole 40000
C-COR.Net Corporation com 125010108 3136 64000 SH Sole 64000
CAM Commerce Solutions Inc. com 131730103 2177 135002 SH Sole 100000 35002
CCC Information Services Grp com 12487q109 253 11750 SH Sole 11750
Candela Corporation com 136907102 4117 299415 SH Sole 247500 51915
Carreker-Antinori Inc. com 144433109 790 62600 SH Sole 50000 12600
Carrier Access Corporation com 144460102 1774 33310 SH Sole 20000 13310
Casey's General Stores com 147528103 283 26000 SH Sole 26000
Catalina Marketing Corp. com 148867104 506 5000 SH Sole 5000
Check Point Software com M22465104 522 3050 SH Sole 2000 1050
Chico's Fas Inc. com 168615102 2906 171400 SH Sole 132000 39400
</TABLE>
1
<PAGE>
Oberweis Asset Management, Inc.
FORM 13F
March 31, 2000
<TABLE>
<CAPTION>
Voting Authority
Value Shares/ Sh/ Put/ Invstmt Other ------------------------
Name of Issuer Title of Class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers Sole Shared None
- ------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
Children's Place com 168905107 694 48700 SH Sole 46000 2700
Cima Labs com 171796105 309 18000 SH Sole 18000
Citrix Systems Inc. com 177376100 556 8400 SH Sole 4000 4400
Cognizant Technology Solutions com 192446102 3237 51800 SH Sole 50000 1800
Cohu, Inc. com 192576106 277 6650 SH Sole 6000 650
Compuware Corporation com 205638109 253 12000 SH Sole 10000 2000
Consolidated Graphics, Inc. com 209341106 138 10750 SH Sole 10750
Continous Software com 21218R104 302 32000 SH Sole 20000 12000
Crown Group, Inc. com 228359105 116 20000 SH Sole 20000
Cunningham Graphics com 231157108 735 29820 SH Sole 20000 9820
Cutter & Buck Inc. com 232217109 1291 96050 SH Sole 67500 28550
Cybex Computer Products com 232522102 1693 45000 SH Sole 45000
Cytyc com 232946103 1254 25980 SH Sole 10000 15980
DRS Technologies com 252456405 276 27800 SH Sole 27800
Diamond Tech Partners, Inc. com 252762109 888 13500 SH Sole 13500
Digital Biometrics Inc. com 253833107 751 91000 SH Sole 50000 41000
Digital Lightwave Inc. com 253855100 3592 57650 SH Sole 48000 9650
Dset Corporation com 262504103 221 12000 SH Sole 12000
Duraswitch Industries, Inc. com 101 15000 SH Sole 15000
ECCS Inc. com 26825H100 2189 151000 SH Sole 140000 11000
EGL, Inc. com 270018104 298 12750 SH Sole 12750
ESS Technology, Inc. com 269151106 968 55300 SH Sole 46000 9300
Elron Electronic com 561 15000 SH Sole 15000
Emmis Broadcasting Corp. - CL com 291525103 393 8442 SH Sole 8442
Exactech, Inc. com 30064E109 169 10000 SH Sole 10000
Excel Technology Inc. com 30067T103 2246 63500 SH Sole 62500 1000
Expeditors Intl Wash, Inc. com 302130109 676 17000 SH Sole 17000
Express Scripts A com 302182100 237 5650 SH Sole 5650
Frenchtex com 357814102 0 25000 SH Sole 25000
Genesis Microchip Inc. com 371933102 1553 71400 SH Sole 50000 21400
Gentex Corp. com 371901109 519 14000 SH Sole 14000
Gentner Communications com 37245J105 3453 170500 SH Sole 100000 70500
Gilat Communications, Ltd. com M50876107 1456 54700 SH Sole 49200 5500
HA-LO Industries, Inc. com 404429102 102 13000 SH Sole 13000
Hain Food Group Inc com 405219106 1766 62360 SH Sole 40000 22360
Hall Kinion & Assoc. com 406069104 1242 51600 SH Sole 40000 11600
Harbinger Corporation com 41145C103 404 13875 SH Sole 13875
Harmonic Lightwaves com 413160102 586 7040 SH Sole 3000 4040
Helix Technology com 240 4000 SH Sole 4000
Hi/fn, Inc. com 428358105 548 8415 SH Sole 8415
Hieco Corp. com 422806109 145 10000 SH Sole 10000
</TABLE>
2
<PAGE>
Oberweis Asset Management, Inc.
FORM 13F
March 31, 2000
<TABLE>
<CAPTION>
Voting Authority
Value Shares/ Sh/ Put/ Invstmt Other ------------------------
Name of Issuer Title of Class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers Sole Shared None
- ------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
Idexx Laboratories, Inc. com 45168d104 214 9200 SH Sole 9200
Ikos Systems Inc. com 451716203 3374 260800 SH Sole 180000 80800
Immucor Inc. com 452526106 212 21500 SH Sole 14000 7500
Inamed Corp. com 453235103 346 7000 SH Sole 7000
Infocure Corporation com 45665A108 532 30600 SH Sole 30000 600
Informix, Corp. com 456779107 508 30000 SH Sole 30000
Insight Enterprises Inc. com 457650103 297 8150 SH Sole 7500 650
Integrated Measurement com 457923100 1273 62675 SH Sole 50000 12675
Intel Corporation com 458140100 467 3540 SH Sole 3540
Interiors, Inc. CL A com 458688108 9 10000 SH Sole 10000
Interpore Intl. com 46062W107 260 31000 SH Sole 20000 11000
Intranet Solutions, Inc. com 460939309 3165 68800 SH Sole 60000 8800
Investment Technology Group com 461450108 225 6382 SH Sole 6382
Jakks Pacific Inc. com 47012E106 431 20000 SH Sole 20000
Jones Medical com 480236108 361 11900 SH Sole 11900
K.V. Pharmaceutical Co. com 482740206 460 17100 SH Sole 17100
Kemet Corporation com 488360108 253 4000 SH Sole 4000
Kent Electronics com 490553104 385 13200 SH Sole 13200
Key Production Company, Inc. com 267 20000 SH Sole 20000
King Pharmaceuticals Inc. com 495582108 5055 160480 SH Sole 133500 26980
Knight Transportation com 499064103 324 18500 SH Sole 18500
Koala Corporation com 499866101 142 10660 SH Sole 6000 4660
Loronix Information Systems com 544183106 218 6000 SH Sole 6000
M G I Pharmaceutical com 552880106 2185 54200 SH Sole 40000 14200
MCI Worldcom Inc. com 98155K102 246 5431 SH Sole 5431
Magic Software Enterprises Ltd com 559166103 2252 118525 SH Sole 90000 28525
Manatron Inc. com 562048108 213 22000 SH Sole 20000 2000
Meade Instruments Corporation com 583062104 690 10000 SH Sole 10000
Measurement Specialties Inc. com 583421102 451 17800 SH Sole 10000 7800
Mercury Computer Systems, Inc. com 589378108 6789 138900 SH Sole 110000 28900
Mercury Interactive Corporation com 589405109 1867 23560 SH Sole 4000 19560
Meridian Resource Corp. com 58977q109 310 80000 SH Sole 80000
Michaels Stores, Inc. com 594087108 782 19200 SH Sole 10000 9200
Micro Component Technology com 91 10000 SH Sole 10000
Microchip Technology, Inc. com 595017104 557 8475 SH Sole 8475
Microsoft Corp. com 594918104 297 2800 SH Sole 2800
Monterey Pasta Co. com 612570101 1675 394200 SH Sole 297000 97200
Motorola Inc. com 620076109 292 2000 SH Sole 2000
NCI Building Systems, Inc. com 628852105 357 19000 SH Sole 19000
National Computer Systems, Inc com 635519101 376 7400 SH Sole 7400
Netsmart Technologies com 64114W306 1521 139050 SH Sole 60000 79050
</TABLE>
3
<PAGE>
Oberweis Asset Management, Inc.
FORM 13F
March 31, 2000
<TABLE>
<CAPTION>
Voting Authority
Value Shares/ Sh/ Put/ Invstmt Other ------------------------
Name of Issuer Title of Class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers Sole Shared None
- ------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
New Horizons Worldwide com 645526104 222 12500 SH Sole 12500
Newfield Exploration com 651290108 282 8000 SH Sole 8000
Nice Systems Ltd. com 653656108 712 10000 SH Sole 10000
Nokia Corporation A com 654902204 222 1000 SH Sole 1000
North American Scientific, Inc com 65715D100 2458 114320 SH Sole 80000 34320
Nova Corp/Georgia com 669784100 359 12325 SH Sole 12325
Occidental Pete Corp. com 674599105 559 26950 SH Sole 26950
P.F. Changs China Bistro com 69333y108 1984 59900 SH Sole 40000 19900
PRWW, Ltd. com 693591109 1528 97000 SH Sole 92000 5000
Patterson Dental Co. com 703412106 291 7600 SH Sole 7600
Peregrine Systems com 71366Q101 1408 21000 SH Sole 20000 1000
Performance Technologies com 71376K102 3617 83280 SH Sole 65000 18280
Photon Dynamics Inc. com 719364101 2108 30550 SH Sole 16000 14550
Polycom Inc. com 73172K104 515 6500 SH Sole 6000 500
Polymedica Corp. com 731738100 8840 150465 SH Sole 120000 30465
Power-One, Inc. com 241 4000 SH Sole 4000
PowerWave Technology com 739363109 1919 15355 SH Sole 7000 8355
Prima Energy Corporation com 741901201 1380 51100 SH Sole 40000 11100
Prinktrak International Inc. com 742574106 130 10000 SH Sole 10000
Prosofttraining.com com 212 9400 SH Sole 9400
QRS Corp. com 74726x105 519 6900 SH Sole 6900
Qlogic Corp com 747277101 4772 35220 SH Sole 30000 5220
Quest Education Corp. com 74835f102 86 10000 SH Sole 10000
RF Micro Devices, Inc. com 749941100 558 4150 SH Sole 4150
RMH Teleservices, Inc. com 749938106 405 41500 SH Sole 20000 21500
Radiant Systems com 75025N102 4546 72300 SH Sole 60000 12300
Radisys Corp. com 750459109 761 12650 SH Sole 10000 2650
Railamerica Inc. com 750753105 135 20000 SH Sole 20000
Rare Hospitality Intl., Inc. com 753820109 292 15000 SH Sole 15000
Rehabilicare Incorporated com 758944102 119 50000 SH Sole 50000
Remedy Corp. com 759548100 486 11535 SH Sole 7000 4535
Right Management Consultants com 766573109 224 24400 SH Sole 24400
Rogue Wave Software com 775369101 130 17000 SH Sole 17000
SBS Broadcasting SA com l8137f102 351 5700 SH Sole 5700
Safety 1st, Inc. com 104 10000 SH Sole 10000
Sagent Technology, Inc. com 786693101 1049 36423 SH Sole 20000 16423
Salton Inc. com 795757103 8400 193650 SH Sole 160000 33650
Sani Tech Industry Inc. com 0 11000 SH Sole 11000
ScanSource, Inc. com 806037107 2123 59810 SH Sole 50000 9810
Sicor Inc. com 825846108 703 67800 SH Sole 67800
Sicor, Inc. com 825846108 1396 134600 SH Sole 130000 4600
</TABLE>
4
<PAGE>
Oberweis Asset Management, Inc.
FORM 13F
March 31, 2000
<TABLE>
<CAPTION>
Voting Authority
Value Shares/ Sh/ Put/ Invstmt Other ------------------------
Name of Issuer Title of Class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers Sole Shared None
- ------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
Siebel Systems Inc. com 826170102 287 2400 SH Sole 2400
Silicon Storage Tech com 827057100 1610 21800 SH Sole 20000 1800
Silicon Valley Bancshares com 827064106 216 3000 SH Sole 3000
Siliconix, Inc. com 827079203 1079 11350 SH Sole 7000 4350
Source Information Management com 836151209 2262 129250 SH Sole 100000 29250
Spartech Corp. com 847220209 392 11400 SH Sole 11400
Spectralink Corp. com 847580107 360 20000 SH Sole 20000
Stericycle, Inc. com 858912108 1744 69750 SH Sole 50000 19750
Steven Madden Ltd. com 556269108 834 43900 SH Sole 35000 8900
Strategic Diagnostics, Inc. com 862700101 114 15000 SH Sole 15000
Suprema Specialties, Inc. com 86859f107 2700 271700 SH Sole 190000 81700
Surmodics, Inc. com 868873100 522 19000 SH Sole 19000
TTI Team Telecom com m88258104 990 30000 SH Sole 30000
Talx Corporation com 874915105 750 39500 SH Sole 30000 9500
Teleflex, Inc. com 879369106 322 9100 SH Sole 9100
Tetra Tech, Inc. com 88162g103 507 21353 SH Sole 21353
The Bisys Group, Inc. com 055472104 346 5196 SH Sole 5196
Tiffany & Co. com 886547108 443 5300 SH Sole 5300
Titan Corporation com 888266103 545 10681 SH Sole 10000 681
Tollgrade Communications com 889542106 540 10180 SH Sole 4000 6180
Transaction Systems Architects com 893416107 367 12700 SH Sole 12700
Transwitch Corporation com 894065101 3696 38450 SH Sole 35500 2950
Triton Energy 'A' com G90751101 1052 30000 SH Sole 10000 20000
US-China Industrial com 90329w302 191 14700 SH Sole 9000 5700
USA Networks, Inc. com 902984103 384 17000 SH Sole 17000
United Natural Foods, Inc. com 911163103 410 27350 SH Sole 27350
V3 Semiconductor Inc. com 918392101 1863 58900 SH Sole 51900 7000
Ventana Medical Systems com 92276H106 1948 45100 SH Sole 40000 5100
Verity Inc. com 92343C106 4515 110800 SH Sole 82400 28400
Videolabs, Inc. com 92657R103 334 81000 SH Sole 46000 35000
Vintage Pete, Inc. com 927460105 1006 50000 SH Sole 50000
Visual Networks, Inc. com 928444108 2009 35400 SH Sole 26000 9400
Vitesse Semiconductor Co. com 928497106 760 7900 SH Sole 7900
Whole Foods Market, Inc. com 966837106 305 7350 SH Sole 7350
Wind River Systems com 973149107 551 15200 SH Sole 15200
Xeta Corporation com 983909102 705 15500 SH Sole 15000 500
Zebra Technologies Corp.-Cl A com 989207105 693 13870 SH Sole 13870
Zevex International, Inc. com 98950E400 4423 395340 SH Sole 300000 95340
Zoll Medical Corporation com 989922109 1384 27010 SH Sole 20000 7010
</TABLE>
5
<PAGE>
Oberweis Asset Management, Inc.
FORM 13F
March 31, 2000
<TABLE>
<CAPTION>
Voting Authority
Value Shares/ Sh/ Put/ Invstmt Other ------------------------
Name of Issuer Title of Class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers Sole Shared None
- ------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
REPORT SUMMARY 203 DATA RECORDS 239091 0 OTHER MANAGERS ON WHOSE BEHALF REPORT IS FILED
</TABLE>
Do not save this screen as a text file. This report automatically creates the
text file 13ftable.txt, which meets all SEC filing requirements. For details on
the location of this text file, see your 705 Report documentation.
6
<PAGE>
FORM 13F SUMARY PAGE
Report Summary:
Number of other Included Managers:
------------------------
Form 13F Information Table Entry Total: 203 Data Records
Form 13F Information Table Value Total: $239,091 (thousandths)
List of Other Included Managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.
[If there are no entries in this list, state "NONE" and omit the column headings
and list entries.]
NONE
