Institutional Manager · CIK 0000937886
OBERWEIS ASSET MANAGEMENT INC/
Lisle, IL · File #028-04688
Latest AUM
$2.73B
Positions
179
Top-10 Concentration
36.0%
Filings
9
Portfolio Value Over Time
2024-03
2024-06
2024-09
2024-12
2025-03
2025-06
2025-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| EXITED | ADMA Biologics, Inc. | 000899104 | -2,712,040 | -$39.8M | $0 |
| EXITED | Sportradar Group | H8088L103 | -1,379,100 | -$37.1M | $0 |
| EXITED | Itron Inc | 465741106 | -284,150 | -$35.4M | $0 |
| EXITED | Stride, Inc. | 86333M108 | -181,800 | -$27.1M | $0 |
| EXITED | Qorvo, Inc. | 74736K101 | -260,900 | -$23.8M | $0 |
| NEW | Globus Medical, Inc.-A | GMED | +270,000 | +$23.6M | $0 |
| NEW | Arcutis Biotherapeutics, Inc. | ARQT | +808,400 | +$23.5M | $0 |
| EXITED | Parsons Corp. | 70202L102 | -272,730 | -$22.6M | $0 |
| NEW | Dana Inc. | DAN | +796,500 | +$18.9M | $0 |
| REDUCE | Lumentum Hldgs, Inc. | LITE | -47,700 | -$17.6M | +$67.7M |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 2025179 pos · $2.73B
- 13F HOLDINGS REPORTQ/E Sep 2025183 pos · $2.61B
- 13F HOLDINGS REPORTQ/E Jun 2025185 pos · $2.30B
- 13F HOLDINGS REPORTQ/E Mar 2025192 pos · $2.01B
- 13F HOLDINGS REPORTQ/E Dec 2024196 pos · $2.12B
- 13F HOLDINGS REPORTQ/E Sep 2024206 pos · $1.95B
- 13F HOLDINGS REPORTQ/E Jun 2024197 pos · $1.63B
- 13F HOLDINGS REPORTQ/E Mar 2024196 pos · $1.38B
- 13F HOLDINGS REPORTQ/E Dec 2023195 pos · $941.5M
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | Lumentum Hldgs, Inc. | LITE | 280,930 | $103.5M | 6.55% |
| 2 | Credo Technology Group | CRDO | 675,388 | $97.2M | 6.15% |
| 3 | Applied Optoelectronics Inc. | AAOI | 2,039,641 | $71.1M | 4.50% |
| 4 | SharkNinja, Inc. | SN | 526,310 | $58.9M | 3.73% |
| 5 | Ambarella, Inc. | AMBA | 617,860 | $43.8M | 2.77% |
| 6 | Rambus, Inc | RMBS | 462,100 | $42.5M | 2.69% |
| 7 | Skywest Inc | SKYW | 382,220 | $38.4M | 2.43% |
| 8 | Encompass Health Corporation | EHC | 358,971 | $38.1M | 2.41% |
| 9 | SiTime Corporation | SITM | 106,396 | $37.6M | 2.38% |
| 10 | Digital Ocean Holdings, Inc. | DOCN | 778,830 | $37.5M | 2.37% |
| 11 | Nova Ltd. | NVMI | 113,285 | $37.2M | 2.35% |
| 12 | Frontdoor, Inc. | FTDR | 610,860 | $35.2M | 2.23% |
| 13 | BrightSpring Health Services | 10950A106 | 908,000 | $34.0M | 2.15% |
| 14 | Macom Technology Solutions | 55405Y100 | 178,960 | $30.7M | 1.94% |
| 15 | Veracyte, Inc. | VCYT | 726,740 | $30.6M | 1.94% |
| 16 | Mercury Systems, Inc. | MRCY | 414,040 | $30.2M | 1.91% |
| 17 | Flowserve Corporation | FLS | 409,941 | $28.4M | 1.80% |
| 18 | Life Time Holdings, Inc. | LTH | 1,059,300 | $28.2M | 1.78% |
| 19 | Waystar Holding Corp. | WAY | 840,600 | $27.5M | 1.74% |
| 20 | Rush Street Interactive, Inc. | RSI | 1,411,710 | $27.4M | 1.74% |