CIK: 0000937886
Total reported value
$3.4B
Reporting period: 2026-03-31 · Number of holdings: 180
OBERWEIS ASSET MANAGEMENT INC/ disclosed 180 holdings in its latest 13F filing for the period ending 2026-03-31, with total reported value of $3.4B and a quarterly turnover rate of 45.2%.
Browse other institutions with $1B to $10B AUMBrowse other institutions starting with "O"
Oberweis Asset Management Inc/'s disclosed holdings carry a Herfindahl concentration index of 0.014 — mathematically equivalent to about 70 equally-sized positions, well below its 180 actual disclosed holdings. That gap points to a strategy built around a small core of high-conviction bets rather than broad diversification.
Position sizes vary widely across the portfolio (a coefficient of variation of 1.26), with a handful of outsized bets alongside many smaller positions.
No strong tilt toward either adding to existing winners or initiating outsized new positions was observed in the latest reported quarter.
Sector classification currently covers about 61% of this portfolio's disclosed value; the remainder includes holdings (e.g. unmapped tickers, options, or other security types) not yet covered by our sector mapping.
Add AAOI
+15.2% $127.7M
Add LITE
-5.2% $83.5M
Trim AMBA
-52.2% -$28.6M
Add DOCN
+19.1% $42.1M
Add DAN
+102.3% $35.3M
Trim FRSH
-97.2% -$24.7M
| # | Ticker | Issuer | Asset Subclass | Weight | Weight Change | Shares Change | 4Q Trend |
|---|---|---|---|---|---|---|---|
| 1 | AAOI | Applied Optoelectronics INC | Stock-Tech | 5.87% | +3.27% | +15.21% | |
| 2 | LITE | Lumentum Holdings INC | Stock-Tech | 5.53% | +1.74% | -5.24% | |
| 3 | CRDO | Credo Technology Group Holding Ltd | Stock-Tech | 2.83% | — | +51.32% | |
| 4 | DOCN | Digitalocean Holdings INC | Stock-Tech | 2.35% | +0.98% | +19.09% | |
| 5 | SN | SharkNinja, Inc. | Stock-Consumer Disc | 1.88% | — | +14.00% | |
| 6 | NVMI | Nova Ltd. | Stock-Other | 1.77% | +0.41% | +21.78% | |
| 7 | DAN | Dana INC | Stock-Other | 1.60% | +0.91% | +102.32% | |
| 8 | BTSG | Brightspring Health Services | Stock-Other | 1.46% | +0.22% | +27.64% | |
| 9 | MTSI | Macom Technology Solutions H | Stock-Tech | 1.42% | +0.30% | +20.63% | |
| 10 | RMBS | Rambus INC | Stock-Tech | 1.34% | — | +13.90% | |
| 11 | CLH | Clean Harbors INC | Stock-Industrials | 1.22% | +0.22% | +23.52% | |
| 12 | SITM | Sitime CORP | Stock-Tech | 1.22% | — | +12.11% | |
| 13 | UCTT | Ultra Clean Holdings INC | Stock-Other | 1.18% | +0.60% | +1.91% | |
| 14 | ECG | Everus Construction Group | Stock-Industrials | 1.14% | +0.33% | +25.69% | |
| 15 | FTDR | Frontdoor INC | Stock-Consumer Disc | 1.12% | — | +17.53% | |
| 16 | CRS | Carpenter Technology | Stock-Industrials | 1.10% | +0.15% | +14.31% | |
| 17 | SKYW | Skywest INC | Stock-Industrials | 1.06% | — | +2.69% | |
| 18 | LSCC | Lattice Semiconductor CORP | Stock-Tech | 1.03% | +0.18% | +19.01% | |
| 19 | GMED | Globus Medical INC - A | Stock-Healthcare | 1.00% | +0.14% | +45.26% | |
| 20 | CAMT | Camtek Ltd. | Stock-Other | 1.00% | +0.15% | +1.78% | |
| 21 | ARQT | Arcutis Biotherapeutics INC | Stock-Other | 0.95% | +0.09% | +68.97% | |
| 22 | FLS | Flowserve CORP | Stock-Industrials | 0.94% | — | +6.04% | |
| 23 | SIMO | Silicon Motion Technol-adr | Stock-Other | 0.94% | +0.14% | +19.57% | |
| 24 | LTH | Life Time Group Holdings INC | Stock-Other | 0.92% | — | +9.55% | |
| 25 | RSI | Rush Street Interactive INC | Stock-Other | 0.92% | — | +1.62% | |
| 26 | FCFS | Firstcash Holdings INC | Stock-Financials | 0.92% | +0.15% | +26.17% | |
| 27 | FSLY | Fastly INC - Class A | Stock-Tech | 0.92% | +0.66% | +55.27% | |
| 28 | TPC | Tutor Perini CORP | Stock-Other | 0.90% | — | +1.73% | |
| 29 | BROS | Dutch Bros Inc-class A | Stock-Consumer Disc | 0.90% | — | +47.96% | |
| 30 | SEI | Solaris Energy Infrastructur | Stock-Energy | 0.89% | +0.27% | +44.97% | |
| 31 | MMSI | Merit Medical Systems INC | Stock-Healthcare | 0.86% | — | +57.84% | |
| 32 | FSS | Federal Signal CORP | Stock-Industrials | 0.85% | +0.19% | +60.74% | |
| 33 | AMSC | American Superconductor CORP | Stock-Other | 0.85% | — | +1.67% | |
| 34 | MRCY | Mercury Systems INC | Stock-Industrials | 0.84% | — | -5.56% | |
| 35 | ACA | Arcosa INC | Stock-Industrials | 0.84% | — | +20.80% | |
| 36 | OSIS | Osi Systems INC | Stock-Tech | 0.84% | — | +5.12% | |
| 37 | CNR | Core Natural Resources INC | Stock-Energy | 0.83% | +0.25% | +51.23% | |
| 38 | WAY | Waystar Holding CORP | Stock-Other | 0.83% | — | +38.89% | |
| 39 | EHC | Encompass Health CORP | Stock-Healthcare | 0.83% | -0.56% | -19.36% | |
| 40 | VCYT | Veracyte INC | Stock-Other | 0.80% | — | +15.56% | |
| 41 | AIR | Aar CORP | Stock-Industrials | 0.79% | — | -10.11% | |
| 42 | ICUI | Icu Medical INC | Stock-Other | 0.78% | — | +21.23% | |
| 43 | LFUS | Littelfuse INC | Stock-Tech | 0.72% | — | +15.25% | |
| 44 | PRIM | Primoris Services CORP | Stock-Industrials | 0.70% | — | +1.71% | |
| 45 | RELY | Remitly Global INC | Stock-Other | 0.67% | +0.16% | +45.02% | |
| 46 | G | Genpact Limited | Stock-Tech | 0.67% | — | +16.34% | |
| 47 | AIZ | Assurant INC | Stock-Financials | 0.66% | — | +23.25% | |
| 48 | BLBD | Blue Bird CORP | Stock-Other | 0.65% | — | +1.72% | |
| 49 | IMAX | Imax CORP | Stock-Other | 0.65% | — | -11.52% | |
| 50 | LEVI | Levi Strauss & Co- Class A | Stock-Other | 0.64% | — | +17.45% |
Performance for Q3 2026
-0.8%
Performance Last 4 Quarters
+53.9%
Based on 80% of reported portfolio value with available pricing
| Period | Holdings | Total value | Stability | Top holdings |
|---|---|---|---|---|
| 2026-03-31 | 180 | $3.4B | 45 | |
| 2025-12-31 | 179 | $2.7B | 38 | |
| 2025-09-30 | 183 | $2.6B | 68 | |
| 2025-06-30 | 185 | $2.3B | 0 | |
| 2025-03-31 | 192 | $2.0B | 100 | |
| 2024-12-31 | 196 | $2.1B | 0 | |
| 2024-09-30 | 206 | $2.0B | 0 | |
| 2024-06-30 | 197 | $1.6B | 0 | |
| 2024-03-31 | 196 | $1.4B | 0 | |
| 2023-12-31 | 192 | $1.1B | 0 | |
| 2023-09-30 | 195 | $941.5M | 0 | |
| 2023-06-30 | 187 | $822.8M | 0 | |
| 2023-03-31 | 174 | $644.5M | 0 | |
| 2022-12-31 | 168 | $470.4M | 0 | |
| 2022-09-30 | 173 | $427.3M | 0 | |
| 2022-06-30 | 164 | $395.1M | 0 | |
| 2022-03-31 | 165 | $499.2M | 0 | |
| 2021-12-31 | 160 | $548.1M | 0 | |
| 2021-09-30 | 162 | $482.9M | 0 | |
| 2021-06-30 | 163 | $456.5M | 100 | |
| 2021-03-31 | 170 | $488.9M | 51 | |
| 2020-12-31 | 138 | $379.8M | 50 | |
| 2020-09-30 | 126 | $297.0M | 46 | |
| 2020-06-30 | 123 | $254.7M | 100 | |
| 2020-03-31 | 172 | $181.2M | 82 | |
| 2019-12-31 | 200 | $300.2M | 100 | |
| 2019-09-30 | 196 | $442.5M | 59 | |
| 2019-06-30 | 196 | $550.4M | 53 | |
| 2019-03-31 | 201 | $498.0M | 71 | |
| 2018-12-31 | 200 | $447.1M | 72 | |
| 2018-09-30 | 209 | $516.0M | 75 | |
| 2018-06-30 | 220 | $397.9M | 56 | |
| 2018-03-31 | 227 | $381.0M | 48 | |
| 2017-12-31 | 234 | $427.5M | 49 | |
| 2017-09-30 | 169 | $359.3M | 69 | |
| 2017-06-30 | 142 | $364.4M | 65 | |
| 2017-03-31 | 139 | $339.3M | 61 | |
| 2016-12-31 | 135 | $334.7M | 36 | |
| 2016-09-30 | 135 | $347.4M | 51 | |
| 2016-06-30 | 170 | $336.5M | 53 | |
| 2016-03-31 | 175 | $346.2M | 55 | |
| 2015-12-31 | 175 | $356.5M | 53 | |
| 2015-09-30 | 165 | $343.2M | 39 | |
| 2015-06-30 | 166 | $378.0M | 40 | |
| 2015-03-31 | 169 | $356.0M | 55 | |
| 2014-12-31 | 127 | $334.9M | 39 | |
| 2014-09-30 | 133 | $365.1M | 50 | |
| 2014-06-30 | 138 | $405.6M | 63 | |
| 2014-03-31 | 149 | $476.2M | 68 | |
| 2013-12-31 | 148 | $412.9M | 47 | |
| 2013-09-30 | 141 | $352.1M | 71 | |
| 2013-06-30 | 147 | $352.7M | 0 |
Oberweis Asset Management Inc/'s most significant position changes for 2026-03-31: New buy: Leonardo Drs INC (DRS); New buy: Indivior Pharmaceuticals INC (INDV); Sold out: Cargurus INC (CARG); New buy: Chime Financial Inc-cl A (CHYM); New buy: Hinge Health Inc-a (HNGE).
| # | Ticker | Issuer | Weight Change | Shares Change | Action |
|---|---|---|---|---|---|
| 1 | AAOI | Applied Optoelectronics INC | +3.3% | +15.21% | Add |
| 2 | LITE | Lumentum Holdings INC | +1.7% | -5.24% | Trim |
| 3 | DOCN | Digitalocean Holdings INC | +1% | +19.09% | Add |
| 4 | DAN | Dana INC | +0.9% | +102.32% | Add |
| 5 | FSLY | Fastly INC - Class A | +0.7% | +55.27% | Add |
| 6 | UCTT | Ultra Clean Holdings INC | +0.6% | +1.91% | Add |
| 7 | NVMI | Nova Ltd. | +0.4% | +21.78% | Add |
| 8 | ECG | Everus Construction Group | +0.3% | +25.69% | Add |
| 9 | MTSI | Macom Technology Solutions H | +0.3% | +20.63% | Add |
| 10 | SEI | Solaris Energy Infrastructur | +0.3% | +44.97% | Add |
| 11 | CNR | Core Natural Resources INC | +0.3% | +51.23% | Add |
| 12 | VIAV | Viavi Solutions INC | +0.3% | +16.75% | Add |
| 13 | BTSG | Brightspring Health Services | +0.2% | +27.64% | Add |
| 14 | CLH | Clean Harbors INC | +0.2% | +23.52% | Add |
| 15 | FSS | Federal Signal CORP | +0.2% | +60.74% | Add |
| 16 | MTDR | Matador Resources Co | +0.2% | +23.16% | Add |
| 17 | ABCB | Ameris Bancorp | +0.2% | +68.48% | Add |
| 18 | LSCC | Lattice Semiconductor CORP | +0.2% | +19.01% | Add |
| 19 | RELY | Remitly Global INC | +0.2% | +45.02% | Add |
| 20 | CRS | Carpenter Technology | +0.2% | +14.31% | Add |
| 21 | CAMT | Camtek Ltd. | +0.2% | +1.78% | Add |
| 22 | FCFS | Firstcash Holdings INC | +0.2% | +26.17% | Add |
| 23 | GMED | Globus Medical INC - A | +0.1% | +45.26% | Add |
| 24 | SIMO | Silicon Motion Technol-adr | +0.1% | +19.57% | Add |
| 25 | ARQT | Arcutis Biotherapeutics INC | +0.1% | +68.97% | Add |
| 26 | ✓ | IBEX Ltd. | -0.3% | -95.78% | Trim |
| 27 | WGS | Genedx Holdings CORP | -0.5% | +31.49% | Add |
| 28 | EHC | Encompass Health CORP | -0.6% | -19.36% | Trim |
| 29 | FRSH | Freshworks Inc-cl A | -0.9% | -97.19% | Trim |
| 30 | AMBA | Ambarella, Inc. | -1.2% | -52.22% | Trim |
| 31 | DRS | Leonardo Drs INC | — | NEW | New buy |
| 32 | INDV | Indivior Pharmaceuticals INC | — | NEW | New buy |
| 33 | CARG | Cargurus INC | — | EXIT | Sold out |
| 34 | CHYM | Chime Financial Inc-cl A | — | NEW | New buy |
| 35 | HNGE | Hinge Health Inc-a | — | NEW | New buy |
| 36 | SXT | Sensient Technologies CORP | — | EXIT | Sold out |
| 37 | GENI | Genius Sports Limited | — | EXIT | Sold out |
| 38 | NVST | Envista Holdings CORP | — | NEW | New buy |
| 39 | SHAK | Shake Shack INC - Class A | — | NEW | New buy |
| 40 | ACIW | Aci Worldwide INC | — | EXIT | Sold out |
| 41 | INDV | Indivior Pharmaceuticals, Inc. | — | EXIT | Sold out |
| 42 | ARLO | Arlo Technologies INC | — | NEW | New buy |
| 43 | CVLT | Commvault Systems INC | — | EXIT | Sold out |
| 44 | MOG-A | Moog Inc-class A | — | NEW | New buy |
| 45 | ATEN | A10 Networks INC | — | NEW | New buy |
| 46 | SBCF | Seacoast Banking Corp/fl | — | NEW | New buy |
| 47 | TPB | Turning Point Brands INC | — | EXIT | Sold out |
| 48 | WK | Workiva INC | — | EXIT | Sold out |
| 49 | AMPX | Amprius Technologies INC | — | NEW | New buy |
| 50 | GDOT | Green Dot Corp-class A | — | EXIT | Sold out |
| Period | Filed | Type | EDGAR |
|---|---|---|---|
| 2026-03-31 | 2026-05-15 | 13F-HR | View on EDGAR |
| 2025-12-31 | 2026-02-17 | 13F-HR | View on EDGAR |
| 2025-09-30 | 2025-11-17 | 13F-HR | View on EDGAR |
| 2025-06-30 | 2025-08-14 | 13F-HR | View on EDGAR |
| 2025-03-31 | 2025-05-15 | 13F-HR | View on EDGAR |
| 2024-12-31 | 2025-02-14 | 13F-HR | View on EDGAR |
| 2024-09-30 | 2024-11-14 | 13F-HR | View on EDGAR |
| 2024-06-30 | 2024-08-14 | 13F-HR | View on EDGAR |
| 2024-03-31 | 2024-05-15 | 13F-HR | View on EDGAR |
| 2023-12-31 | 2024-02-14 | 13F-HR | View on EDGAR |
| 2023-09-30 | 2023-11-14 | 13F-HR | View on EDGAR |
| 2023-06-30 | 2023-08-14 | 13F-HR | View on EDGAR |
| 2023-03-31 | 2023-05-15 | 13F-HR | View on EDGAR |
| 2022-12-31 | 2023-02-14 | 13F-HR | View on EDGAR |
| 2022-09-30 | 2022-11-14 | 13F-HR | View on EDGAR |
| 2022-06-30 | 2022-08-15 | 13F-HR | View on EDGAR |
| 2022-03-31 | 2022-05-16 | 13F-HR | View on EDGAR |
| 2021-12-31 | 2022-02-14 | 13F-HR | View on EDGAR |
| 2021-09-30 | 2021-11-15 | 13F-HR | View on EDGAR |
| 2021-06-30 | 2021-08-16 | 13F-HR | View on EDGAR |
| 2021-03-31 | 2021-05-17 | 13F-HR | View on EDGAR |
| 2020-12-31 | 2021-02-16 | 13F-HR | View on EDGAR |
| 2020-09-30 | 2020-11-16 | 13F-HR | View on EDGAR |
| 2020-06-30 | 2020-08-14 | 13F-HR | View on EDGAR |
| 2020-03-31 | 2020-05-15 | 13F-HR | View on EDGAR |
| 2019-12-31 | 2020-02-14 | 13F-HR | View on EDGAR |
| 2019-09-30 | 2019-11-14 | 13F-HR | View on EDGAR |
| 2019-06-30 | 2019-08-14 | 13F-HR | View on EDGAR |
| 2019-03-31 | 2019-05-15 | 13F-HR | View on EDGAR |
| 2018-12-31 | 2019-02-14 | 13F-HR | View on EDGAR |
| 2018-09-30 | 2018-11-14 | 13F-HR | View on EDGAR |
| 2018-06-30 | 2018-08-14 | 13F-HR | View on EDGAR |
| 2018-03-31 | 2018-05-15 | 13F-HR | View on EDGAR |
| 2017-12-31 | 2018-02-14 | 13F-HR | View on EDGAR |
| 2017-09-30 | 2017-11-13 | 13F-HR | View on EDGAR |
| 2017-06-30 | 2017-08-14 | 13F-HR | View on EDGAR |
| 2017-03-31 | 2017-05-15 | 13F-HR | View on EDGAR |
| 2016-12-31 | 2017-02-14 | 13F-HR | View on EDGAR |
| 2016-09-30 | 2016-11-14 | 13F-HR | View on EDGAR |
| 2016-06-30 | 2016-08-15 | 13F-HR | View on EDGAR |
| 2016-03-31 | 2016-05-16 | 13F-HR | View on EDGAR |
| 2015-12-31 | 2016-02-16 | 13F-HR | View on EDGAR |
| 2015-09-30 | 2015-11-13 | 13F-HR | View on EDGAR |
| 2015-06-30 | 2015-08-14 | 13F-HR | View on EDGAR |
| 2015-03-31 | 2015-05-15 | 13F-HR | View on EDGAR |
| 2014-12-31 | 2015-02-13 | 13F-HR | View on EDGAR |
| 2014-09-30 | 2014-11-14 | 13F-HR | View on EDGAR |
| 2014-06-30 | 2014-08-14 | 13F-HR | View on EDGAR |
| 2014-03-31 | 2014-05-15 | 13F-HR | View on EDGAR |
| 2013-12-31 | 2014-02-14 | 13F-HR | View on EDGAR |
| 2013-09-30 | 2013-11-14 | 13F-HR | View on EDGAR |
| 2013-06-30 | 2013-08-14 | 13F-HR | View on EDGAR |
Institutions with a similar AUM
CIK 0001902501
Total reported value
$3.4B
3,174 stks
2026-06-30
AUM within 0.2% of this institution
CIK 0001539976
Total reported value
$3.4B
163 stks
2014-12-31
Stale — no recent filing
AUM within 0.2% of this institution
CIK 0001556218
Total reported value
$3.4B
305 stks
2026-03-31
AUM within 0.2% of this institution
Institutions with overlapping top holdings
CIK 0001584087
Total reported value
$262.6M
130 stks
2026-03-31
2 of the top 5 holdings overlap, including Applied Optoelectronics INC
CIK 0001965005
Total reported value
$597.7M
22 stks
2026-03-31
2 of the top 5 holdings overlap, including Credo Technology Group Holding Ltd
CIK 0001082327
Total reported value
$29.7B
497 stks
2026-03-31
1 of the top 5 holdings overlap, including Lumentum Holdings INC