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OBERWEIS ASSET MANAGEMENT INC/ — 13F Holdings & Portfolio

CIK 937886 · latest 13F-HR filed 2026-05-15

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OBERWEIS ASSET MANAGEMENT INC/ manages $3.39B in 13F-reported U.S. long-equity assets across 180 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are AAOI (5.87%), LITE (5.53%), CRDO (2.83%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 22 new positions, exited 21, added to 97, and trimmed 44.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

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AUM

$3.39B

Long-equity book

Holdings

180

Distinct positions

Period

2026-03-31

Filed 2026-05-15

Q/Q Activity

+22 / −21 / ↑97 / ↓44

vs 2025-12-31

Firm Profile & Key People
Name Title / Status Ownership Type

Top Adds (vs prior quarter)

  • Applied Optoelectronics Inc.$127.7M +179.6%
  • Lumentum Hldgs, Inc.$83.5M +80.7%
  • DigitalOcean Holdings, Inc.$42.1M +112.3%
  • Dana Inc.$35.3M +186.5%
  • Fastly, Inc.$24.1M +343.2%
Show all 97 →

Top Trims

  • Ambarella, Inc.-$28.6M -65.3%
  • Freshworks, Inc.-$24.7M -98.2%
  • Encompass Health Corporation-$10.1M -26.5%
  • Genedx Holdings Corp.-$9.1M -35.1%
  • IBEX Ltd.-$9.0M -97.0%
Show all 44 →

New Positions

  • Leonardo DRS, Inc.$20.0M
  • Indivior Plc$19.9M
  • Chime Financial Inc.$19.4M
  • Hinge Health, Inc.$18.0M
  • Envista Holdings Corp.$16.9M
Show all 22 →

Exited Positions

  • CarGurus, Inc.$19.9M
  • Sensient Technologies Corp.$17.7M
  • Genius Sports Ltd.$17.5M
  • ACI Worldwide Inc.$15.8M
  • Indivior Plc$15.2M
Show all 21 →
All Holdings

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 Applied Optoelectronics Inc. AAOI 03823U102 $198.8M 5.87% 2,349,969 SH
2 Lumentum Hldgs, Inc. LITE 55024U109 $187.1M 5.53% 266,222 SH
3 Credo Technology Group CRDO G25457105 $95.9M 2.83% 1,021,968 SH
4 DigitalOcean Holdings, Inc. DOCN 25402D102 $79.6M 2.35% 927,505 SH
5 SharkNinja, Inc. SN G8068L108 $63.5M 1.88% 599,970 SH
6 Nova Ltd. NVMI M7516K103 $59.9M 1.77% 137,955 SH
7 Dana Inc. DAN 235825205 $54.2M 1.60% 1,611,500 SH
8 BrightSpring Health Services BTSG 10950A106 $49.4M 1.46% 1,158,970 SH
9 Macom Technology Solutions MTSI 55405Y100 $47.9M 1.42% 215,886 SH
10 Rambus, Inc RMBS 750917106 $45.3M 1.34% 526,316 SH
11 Clean Harbors, Inc. CLH 184496107 $41.4M 1.22% 144,355 SH
12 SiTime Corporation SITM 82982T106 $41.2M 1.22% 119,281 SH
13 Ultra Clean Holdings UCTT 90385V107 $39.8M 1.18% 640,476 SH
14 Everus Construction Group ECG 300426103 $38.6M 1.14% 326,533 SH
15 Frontdoor, Inc. FTDR 35905A109 $38.0M 1.12% 717,960 SH
16 Carpenter Technology Corp. CRS 144285103 $37.2M 1.10% 94,433 SH
17 Skywest Inc SKYW 830879102 $36.0M 1.06% 392,499 SH
18 Lattice Semiconductor Corporat LSCC 518415104 $34.7M 1.03% 374,436 SH
19 Globus Medical, Inc.-A GMED 379577208 $33.8M 1.00% 392,200 SH
20 Camtek, Ltd. CAMT M20791105 $33.8M 1.00% 222,780 SH
21 Arcutis Biotherapeutics, Inc. ARQT 03969K108 $32.2M 0.95% 1,365,941 SH
22 Flowserve Corporation FLS 34354P105 $32.0M 0.94% 434,681 SH
23 Silicon Motion Techn ADR SIMO 82706C108 $31.7M 0.94% 282,550 SH
24 Life Time Holdings, Inc. LTH 53190C102 $31.3M 0.92% 1,160,500 SH
25 Rush Street Interactive, Inc. RSI 782011100 $31.2M 0.92% 1,434,560 SH
26 FirstCash Holdings, Inc FCFS 33768G107 $31.1M 0.92% 165,665 SH
27 Fastly, Inc. FSLY 31188V100 $31.1M 0.92% 1,071,022 SH
28 Tutor Perini Corp. TPC 901109108 $30.4M 0.90% 393,900 SH
29 Dutch Bros., Inc. BROS 26701L100 $30.3M 0.90% 598,493 SH
30 Solaris Energy Infrastructur SEI 83418M103 $30.1M 0.89% 531,889 SH
31 Merit Medical System Inc MMSI 589889104 $29.2M 0.86% 424,209 SH
32 Federal Signal Corp. FSS 313855108 $28.9M 0.85% 267,634 SH
33 American Superconductor AMSC 030111207 $28.8M 0.85% 849,900 SH
34 Mercury Systems, Inc. MRCY 589378108 $28.5M 0.84% 391,023 SH
35 Arcosa, Inc. ACA 039653100 $28.4M 0.84% 267,700 SH
36 Osi Systems, Inc. OSIS 671044105 $28.3M 0.84% 106,593 SH
37 Core Natural Resources, Inc. CNR 218937100 $28.3M 0.83% 269,800 SH
38 Waystar Holding Corp. WAY 946784105 $28.1M 0.83% 1,167,474 SH
39 Encompass Health Corporation EHC 29261A100 $28.0M 0.83% 289,485 SH
40 Veracyte, Inc. VCYT 92337F107 $27.1M 0.80% 839,834 SH
41 AAR Corp. AIR 000361105 $26.8M 0.79% 245,125 SH
42 ICU Medical, Inc. ICUI 44930G107 $26.3M 0.78% 203,710 SH
43 Littelfuse, Inc. LFUS 537008104 $24.4M 0.72% 71,800 SH
44 Primoris Services Corp. PRIM 74164F103 $23.8M 0.70% 166,100 SH
45 Remitly Global, Inc. RELY 75960P104 $22.8M 0.67% 1,454,300 SH
46 Genpact Ltd. G G3922B107 $22.6M 0.67% 606,832 SH
47 Assurant, Inc. AIZ 04621X108 $22.3M 0.66% 102,300 SH
48 Blue Bird Corporation BLBD 095306106 $22.1M 0.65% 389,238 SH
49 Imax Corp. IMAX 45245E109 $21.9M 0.65% 577,139 SH
50 Levi Strauss & Co. LEVI 52736R102 $21.6M 0.64% 1,167,300 SH
Filing History
Period Filed AUM Holdings Accession
2026-03-31 2026-05-15 $3.39B 180 0001213900-26-057307
2025-12-31 2026-02-17 $2.73B 179 0001213900-26-017101
2025-09-30 2025-11-17 $2.61B 183 0001213900-25-111225