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OBERWEIS ASSET MANAGEMENT INC/ — 13F Holdings & Portfolio

CIK 937886 · latest 13F-HR filed 2026-08-14

Backtest portfolio

OBERWEIS ASSET MANAGEMENT INC/ manages $4.84B in 13F-reported U.S. long-equity assets across 176 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are CRDO (5.69%), AAOI (5.48%), DOCN (3.02%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 23 new positions and exited 27; 120 existing positions rose in reported value and 25 fell.

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
$4.84B

Long-equity book

Holdings
176

Distinct positions

Period
2026-06-30

Filed 2026-08-14

Q/Q Activity
+23 / −27 / ↑120 / ↓25

vs 2026-03-31

Portfolio charts

Latest quarter's book, what changed, and how the portfolio has evolved across filings.

Portfolio map

Q2 26
CRDO5.7% · -1%AAOI5.5% · -24%DOCN3.0% · +0%SIMO2.2% · +12%UCTT1.9% · +1%SN1.9% · -1%SITM1.8% · +0%BTSG1.7% · +2%HNGE1.5% · +84%RMBS1.4% · +0%MTSI1.4% · -17%LITE1.3% · -73%LSCC1.2% · +5%NVMI1.2% · -21%CRS1.2% · -1%FTDR1.2% · +0%ECG1.1% · +0%VCYT1.1% · +4%POWL1.1% · +426%LTH1.0% · +2%RSI1.0% · +14%MRCY1.0% · +0%BROS1.0% · +10%CLH0.9% · +6%SEI0.9% · +6%DIOD0.9% · +84%ACA0.9% · +10%BLBD0.9% · +36%CAMT0.9% · +14%LIVN0.8% · +55%AMSC0.8% · +16%MXL0.8% · newGMED0.8% · +31%NOVT0.8% · newSKYW0.8% · -2%VIAV0.8% · +34%MOG.A0.8% · +93%LFUS0.8% · +11%ARQT0.7% · +0%FCFS0.7% · +0%BLLN0.7% · newDAN0.7% · -18%ESI0.7% · newAIR0.7% · +0%RELY0.7% · +8%ICUI0.7% · +16%FSS0.7% · +0%OUST0.7% · newLEVI0.7% · +16%MMSI0.7% · +12%AIZ0.7% · +19%WAY0.7% · +36%CECO0.7% · +165%LQDA0.7% · +9%EHC0.7% · +10%INDV0.7% · +19%CGNX0.6% · newGVA0.6% · newPDFS0.6% · newNVST0.6% · +68%

Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.

Sector mix

% of 13F value

Sectors from each company's SIC code; funds and ETFs grouped separately.

Biggest buys and sells

Q1 26 → Q2 26

Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.

13F assets and positions

4 quarters

Total reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.

Top positions over time

reported value

The eight largest current positions, valued at each quarter end.

Concentration

top 10 = 26.6%

Cumulative share of the portfolio held in the largest N positions.

Firm Profile & Key People
Assets Under Management
$5.06B
Discretionary
$5.06B
Employees
31
Accounts
110
Address
3333 WARRENVILLE ROAD
SUITE 500
LISLE, IL 60532
Phone
(630) 577-2300
Website
Name Title / Status Ownership Type
OBERWEIS, JAMES, WALTER ControlCHAIRMAN, PRESIDENT, SHAREHOLDER AND DIRECTOR50–75%Individual
HANNEMANN, ERIC, VICARYCHIEF FINANCIAL OFFICER, TREASURERLess than 5%Individual
JOYCE, THOMAS, PATRICKCHIEF COMPLIANCE OFFICER, SECRETARYLess than 5%Individual
OBERWEIS, JAMES, DONALDSHAREHOLDER10–25%Individual

Quarter-over-quarter changes

Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.

OBERWEIS ASSET MANAGEMENT INC/ Holdings (2026-06-30)

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 Credo Technology Group CRDO G25457105 $275.6M 5.69% 1,013,428 SH
2 Applied Optoelectronics Inc. AAOI 03823U102 $265.4M 5.48% 1,791,127 SH
3 DigitalOcean Holdings, Inc. DOCN 25402D102 $146.0M 3.02% 930,005 SH
4 Silicon Motion Techn ADR SIMO 82706C108 $105.4M 2.18% 316,350 SH
5 Ultra Clean Holdings UCTT 90385V107 $92.3M 1.91% 647,276 SH
6 SharkNinja, Inc. SN G8068L108 $90.4M 1.87% 593,500 SH
7 SiTime Corporation SITM 82982T106 $89.1M 1.84% 119,501 SH
8 BrightSpring Health Services BTSG 10950A106 $82.7M 1.71% 1,185,280 SH
9 Hinge Health, Inc. HNGE 433313103 $71.0M 1.47% 855,476 SH
10 Rambus, Inc RMBS 750917106 $70.0M 1.45% 527,016 SH
11 Macom Technology Solutions MTSI 55405Y100 $68.2M 1.41% 179,356 SH
12 Lumentum Hldgs, Inc. LITE 55024U109 $61.9M 1.28% 72,185 SH
13 Lattice Semiconductor Corporat LSCC 518415104 $59.9M 1.24% 391,816 SH
14 Nova Ltd. NVMI M7516K103 $59.0M 1.22% 108,675 SH
15 Carpenter Technology Corp. CRS 144285103 $57.5M 1.19% 93,273 SH
16 Frontdoor, Inc. FTDR 35905A109 $55.8M 1.15% 719,060 SH
17 Everus Construction Group ECG 300426103 $54.5M 1.13% 328,183 SH
18 Veracyte, Inc. VCYT 92337F107 $51.5M 1.07% 877,734 SH
19 Powell Industries Inc. POWL 739128106 $51.4M 1.06% 179,521 SH
20 Life Time Holdings, Inc. LTH 53190C102 $48.6M 1.00% 1,189,620 SH
21 Rush Street Interactive, Inc. RSI 782011100 $48.4M 1.00% 1,627,930 SH
22 Mercury Systems, Inc. MRCY 589378108 $48.0M 0.99% 392,723 SH
23 Dutch Bros., Inc. BROS 26701L100 $47.1M 0.97% 656,093 SH
24 Clean Harbors, Inc. CLH 184496107 $45.9M 0.95% 153,475 SH
25 Solaris Energy Infrastructur SEI 83418M103 $45.4M 0.94% 564,581 SH
26 Diodes, Inc. DIOD 254543101 $45.3M 0.94% 413,750 SH
27 Arcosa, Inc. ACA 039653100 $42.9M 0.89% 295,450 SH
28 Blue Bird Corporation BLBD 095306106 $41.8M 0.86% 529,838 SH
29 Camtek, Ltd. CAMT M20791105 $41.3M 0.85% 253,380 SH
30 LivaNova Plc LIVN G5509L101 $41.1M 0.85% 500,150 SH
31 American Superconductor AMSC 030111207 $41.0M 0.85% 987,500 SH
32 Maxlinear, Inc. Class A MXL 57776J100 $40.9M 0.85% 319,500 SH
33 Globus Medical, Inc.-A GMED 379577208 $40.5M 0.84% 512,100 SH
34 Novanta, Inc. NOVT 67000B104 $39.6M 0.82% 244,260 SH
35 Skywest Inc SKYW 830879102 $38.1M 0.79% 383,799 SH
36 Viavi Solutions, Inc. VIAV 925550105 $37.9M 0.78% 793,600 SH
37 Moog Inc. - A MOG.A 615394202 $36.8M 0.76% 86,735 SH
38 Littelfuse, Inc. LFUS 537008104 $36.3M 0.75% 79,800 SH
39 Arcutis Biotherapeutics, Inc. ARQT 03969K108 $36.0M 0.74% 1,372,941 SH
40 FirstCash Holdings, Inc FCFS 33768G107 $35.9M 0.74% 166,105 SH
41 Billiontoone, Inc. BLLN 090168105 $35.9M 0.74% 299,030 SH
42 Dana Inc. DAN 235825205 $35.9M 0.74% 1,318,300 SH
43 Element Solutions, Inc. ESI 28618M106 $35.3M 0.73% 740,100 SH
44 AAR Corp. AIR 000361105 $35.2M 0.73% 246,325 SH
45 Remitly Global, Inc. RELY 75960P104 $35.2M 0.73% 1,570,400 SH
46 ICU Medical, Inc. ICUI 44930G107 $34.8M 0.72% 237,050 SH
47 Federal Signal Corp. FSS 313855108 $34.6M 0.71% 269,084 SH
48 Ouster, Inc. OUST 68989M202 $34.1M 0.71% 545,810 SH
49 Levi Strauss & Co. LEVI 52736R102 $33.7M 0.70% 1,358,100 SH
50 Merit Medical System Inc MMSI 589889104 $32.8M 0.68% 473,409 SH
Filing History
Period Filed AUM Holdings Accession
2026-06-30 2026-08-14 $4.84B 176 0001213900-26-089777
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
Filer Information
Address
3333 WARRENVILLE ROAD
SUITE 500
LISLE, IL 60532
Phone
(630) 577-2300
Filing Manager
OBERWEIS ASSET MANAGEMENT INC/
LISLE, IL
Signatory
Thomas P. Joyce
Chief Compliance Officer