OBERWEIS ASSET MANAGEMENT INC/
CIK 937886 · EDGAR ↗
- sum of disclosed values for 2026-03-31; 0 positions have no disclosed value and are left out of the sum, counted here rather than dropped
- $3.4B
- every reported holding for this filer and quarter, including ones with no disclosed value
- 180
- positions with no comparable holding in the prior quarter (kind new), 2026-03-31
- 22
- positions absent from this quarter's filing after being held last quarter (kind exit), 2026-03-31 — inferred from absence, not a sale record
- 21
Quarter-end snapshot, filed up to 45 days later — not current holdings. What a 13F covers ↓
Changes · Quarter ended 2026-03-31. Newest filing in this build: 2026-07-31. Per-row filing dates are on each receipt.
by shares · How classified ↗Period
| The reviewed ticker for the filed issuer name and share class, the same mapping the Reported positions table uses. Symbols are never inferred from names; — means no reviewed mapping. | position matched across quarters by exact reported CUSIP over a registry gap — never a name match | NEW / ADD / TRIM / EXIT by share count · NO CHANGE = same shares; the value moved with price, so never an ADD or a TRIM · EXIT = absent this quarter (disposed, delisted, confidential, or reported by an affiliate) — the filing does not say which · NO PRIOR = no comparable prior quarter on record (a first filing, or a quarter filed inside an affiliate's report), so not called a new stake · n/c = not classifiable: value undisclosed on one side of the pair, or neither shares nor value can classify it · †v: the reported share count is unchanged across the pair; this build's data classified the change from its reported value; builds from 2026-09-10 on read it as NO CHANGE | derived by Public Filings from the published data; “no value” means the source did not disclose a usable value — never zero | Prev value | Curr value | Prev shares | Curr shares | |
|---|---|---|---|---|---|---|---|---|
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:17760 · issuer key iss:150 | ADD | +$128M | +310,328 | $71.1M | $199M | 2,039,641 | 2,349,969 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:17670 · issuer key iss:1145 | TRIM | +$83.5M | −14,708 | $104M | $187M | 280,930 | 266,222 |
| — | share class as filed: COM · position key pos:15416 · issuer key iss:2080 | ADD | −$1.2M | +346,580 | $97.2M | $95.9M | 675,388 | 1,021,968 |
| — | share class as filed: COM · position key pos:13589 · issuer key iss:584 | ADD | +$42.1M | +148,675 | $37.5M | $79.6M | 778,830 | 927,505 |
| — | share class as filed: COM · position key pos:10705 · issuer key iss:2209 | ADD | +$4.6M | +73,660 | $58.9M | $63.5M | 526,310 | 599,970 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:13280 · issuer key iss:2278 | ADD | +$22.7M | +24,670 | $37.2M | $59.9M | 113,285 | 137,955 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:15579 · issuer key iss:555 | ADD | +$35.3M | +815,000 | $18.9M | $54.2M | 796,500 | 1,611,500 |
| — | share class as filed: COM · position key pos:18251 · issuer key iss:315 | ADD | +$15.4M | +250,970 | $34.0M | $49.4M | 908,000 | 1,158,970 |
| — | share class as filed: COM · position key pos:16514 · issuer key iss:1163 | ADD | +$17.3M | +36,926 | $30.7M | $47.9M | 178,960 | 215,886 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:17656 · issuer key iss:1520 | ADD | +$2.8M | +64,216 | $42.5M | $45.3M | 462,100 | 526,316 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:10478 · issuer key iss:460 | ADD | +$14.0M | +27,485 | $27.4M | $41.4M | 116,870 | 144,355 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:12212 · issuer key iss:1668 | ADD | +$3.6M | +12,885 | $37.6M | $41.2M | 106,396 | 119,281 |
| — | share class as filed: COM · position key pos:10837 · issuer key iss:1850 | ADD | +$23.9M | +11,976 | $15.9M | $39.8M | 628,500 | 640,476 |
| — | share class as filed: COM · position key pos:10574 · issuer key iss:698 | ADD | +$16.3M | +66,733 | $22.2M | $38.6M | 259,800 | 326,533 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:12120 · issuer key iss:783 | ADD | +$2.7M | +107,100 | $35.2M | $38.0M | 610,860 | 717,960 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:15744 · issuer key iss:402 | ADD | +$11.2M | +11,822 | $26.0M | $37.2M | 82,611 | 94,433 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:15605 · issuer key iss:1673 | ADD | −$2.3M | +10,279 | $38.4M | $36.0M | 382,220 | 392,499 |
| — | share class as filed: COM · position key pos:15974 · issuer key iss:1099 | ADD | +$11.6M | +59,800 | $23.2M | $34.7M | 314,636 | 374,436 |
| — | share class as filed: COM · position key pos:17000 · issuer key iss:829 | ADD | +$10.2M | +122,200 | $23.6M | $33.8M | 270,000 | 392,200 |
| — | share class as filed: COM · position key sid:sec:prov:56bae275e7c8ff6b3019599a71e87dec · issuer key cusip6:M20791 | ADD | +$10.5M | +3,900 | $23.3M | $33.8M | 218,880 | 222,780 |
Flags: no row carries a flag.
1–20 of the 100 changes on this page
1–100 of 191 changes
Mark-to-market only (no share change) · 10
Positions whose share count is identical in both quarters; the value changed with price, not with a decision.
| The reviewed ticker for the filed issuer name and share class, the same mapping the Reported positions table uses. Symbols are never inferred from names; — means no reviewed mapping. | position matched across quarters by exact reported CUSIP over a registry gap — never a name match | NEW / ADD / TRIM / EXIT by share count · NO CHANGE = same shares; the value moved with price, so never an ADD or a TRIM · EXIT = absent this quarter (disposed, delisted, confidential, or reported by an affiliate) — the filing does not say which · NO PRIOR = no comparable prior quarter on record (a first filing, or a quarter filed inside an affiliate's report), so not called a new stake · n/c = not classifiable: value undisclosed on one side of the pair, or neither shares nor value can classify it · †v: the reported share count is unchanged across the pair; this build's data classified the change from its reported value; builds from 2026-09-10 on read it as NO CHANGE | derived by Public Filings from the published data; “no value” means the source did not disclose a usable value — never zero | Prev value | Curr value | Prev shares | Curr shares | |
|---|---|---|---|---|---|---|---|---|
| — | share class as filed: COM · position key pos:13259 · issuer key iss:925 | NO CHANGE | +$77.8K | 0 | $1.1M | $1.2M | 24,000 | 24,000 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:11825 · issuer key iss:1225 | NO CHANGE | −$302K | 0 | $1.3M | $987K | 2,665 | 2,665 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:15142 · issuer key iss:89 | NO CHANGE | −$48.3K | 0 | $595K | $546K | 1,900 | 1,900 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:17821 · issuer key iss:89 | NO CHANGE | −$43.6K | 0 | $508K | $465K | 1,620 | 1,620 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:14206 · issuer key iss:1193 | NO CHANGE | −$47.0K | 0 | $378K | $331K | 662 | 662 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:16392 · issuer key iss:1549 | NO CHANGE | −$23.8K | 0 | $349K | $325K | 1,450 | 1,450 |
| — | share class as filed: ETF · position key pos:11237 · issuer key iss:1601 | NO CHANGE | +$22.9K | 0 | $268K | $290K | 675 | 675 |
| — | share class as filed: PFD · position key pos:15428 · issuer key iss:1955 | NO CHANGE | −$12.8K | 0 | $273K | $260K | 225 | 225 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:15892 · issuer key iss:7 | NO CHANGE | −$1.1K | 0 | $221K | $219K | 2,000 | 2,000 |
| — | share class as filed: COM · position key cusip:98401A106 · issuer key cusip6:98401A | NO CHANGE | $0 | 0 | $0 | $0 | 140,000 | 140,000 |
Flags: no row carries a flag.
Holdings without a security ID are counted, not compared. Method ↗
Reported positions — 2026-03-31
179 issuers · 180 rowsViewThis build carries one quarter for this manager: 2026-03-31. Notable managers carry four published quarters, others two.
| This list carries reported issuer names and security identities, without a dated ticker mapping. Symbols are not inferred from names. | a position composed from a base filing plus NEW-HOLDINGS amendments keeps every source row here; the composition's latest filed date is the one shown served from this build's published holdings (derived from the filer's own reported rows); every row resolves to its filing | Share of total reported value, calculated only when the full position list has disclosed values. This is 13F long value, not total assets. | value undisclosed on the filing: retained and counted, excluded from sums, never shown as $0 | Shares | Wt |
|---|---|---|---|---|---|
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Applied Optoelectronics Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $199M | 2,349,969 | 5.9% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Lumentum Hldgs, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $187M | 266,222 | 5.5% | |
| — | Credo Technology Group · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $95.9M | 1,021,968 | 2.8% | |
| — | DigitalOcean Holdings, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $79.6M | 927,505 | 2.3% | |
| — | SharkNinja, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $63.5M | 599,970 | 1.9% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Nova Ltd. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $59.9M | 137,955 | 1.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Dana Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $54.2M | 1,611,500 | 1.6% | |
| — | BrightSpring Health Services · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $49.4M | 1,158,970 | 1.5% | |
| — | Macom Technology Solutions · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $47.9M | 215,886 | 1.4% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Rambus, Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $45.3M | 526,316 | 1.3% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Clean Harbors, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $41.4M | 144,355 | 1.2% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | SiTime Corporation · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $41.2M | 119,281 | 1.2% | |
| — | Ultra Clean Holdings · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $39.8M | 640,476 | 1.2% | |
| — | Everus Construction Group · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $38.6M | 326,533 | 1.1% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Frontdoor, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $38.0M | 717,960 | 1.1% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Carpenter Technology Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $37.2M | 94,433 | 1.1% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Skywest Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $36.0M | 392,499 | 1.1% | |
| — | Lattice Semiconductor Corporat · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $34.7M | 374,436 | 1.0% | |
| — | Globus Medical, Inc.-A · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $33.8M | 392,200 | 1.0% | |
| — | Camtek, Ltd. · COM CUSIP M20791105 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $33.8M | 222,780 | 1.0% | |
| — | Arcutis Biotherapeutics, Inc. · COM CUSIP 03969K108 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $32.2M | 1,365,941 | 1.0% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Flowserve Corporation · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $32.0M | 434,681 | 0.9% | |
| — | Silicon Motion Techn ADR · COM CUSIP 82706C108 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $31.7M | 282,550 | 0.9% | |
| — | Life Time Holdings, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $31.3M | 1,160,500 | 0.9% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Rush Street Interactive, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $31.2M | 1,434,560 | 0.9% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | FirstCash Holdings, Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $31.1M | 165,665 | 0.9% | |
| — | Fastly, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $31.1M | 1,071,022 | 0.9% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Tutor Perini Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $30.4M | 393,900 | 0.9% | |
| — | Dutch Bros., Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $30.3M | 598,493 | 0.9% | |
| — | Solaris Energy Infrastructur · COM CUSIP 83418M103 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $30.1M | 531,889 | 0.9% | |
| — | Merit Medical System Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $29.2M | 424,209 | 0.9% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Federal Signal Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $28.9M | 267,634 | 0.9% | |
| — | American Superconductor · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $28.8M | 849,900 | 0.8% | |
| — | Mercury Systems, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $28.5M | 391,023 | 0.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Arcosa, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $28.4M | 267,700 | 0.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Osi Systems, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $28.3M | 106,593 | 0.8% | |
| — | Core Natural Resources, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $28.3M | 269,800 | 0.8% | |
| — | Waystar Holding Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $28.1M | 1,167,474 | 0.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Encompass Health Corporation · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $28.0M | 289,485 | 0.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Veracyte, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $27.1M | 839,834 | 0.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | AAR Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $26.8M | 245,125 | 0.8% | |
| — | ICU Medical, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $26.3M | 203,710 | 0.8% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Littelfuse, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $24.4M | 71,800 | 0.7% | |
| — | Primoris Services Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $23.8M | 166,100 | 0.7% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Remitly Global, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $22.8M | 1,454,300 | 0.7% | |
| — | Genpact Ltd. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $22.6M | 606,832 | 0.7% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Assurant, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $22.3M | 102,300 | 0.7% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Blue Bird Corporation · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $22.1M | 389,238 | 0.7% | |
| — | Imax Corp. · COM CUSIP 45245E109 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $21.9M | 577,139 | 0.6% | |
| — | Levi Strauss & Co. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $21.6M | 1,167,300 | 0.6% | |
| — | Alphatec Hldgs Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $20.8M | 1,908,293 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | nLIGHT Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $20.7M | 363,010 | 0.6% | |
| — | National Vision Holdings, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $20.7M | 797,780 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Ameris Bancorp · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $20.6M | 263,500 | 0.6% | |
| — | LivaNova Plc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $20.5M | 321,900 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Leonardo DRS, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $20.0M | 449,500 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Urban Outfitters, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $19.9M | 314,792 | 0.6% | |
| — | Indivior Plc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $19.9M | 653,413 | 0.6% | |
| — | Grand Canyon Education, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $19.9M | 116,900 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Vistance Networks, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $19.9M | 1,092,012 | 0.6% | |
| — | Matador Resources Company · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $19.8M | 312,700 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Viavi Solutions, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $19.7M | 593,200 | 0.6% | |
| — | Chime Financial Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $19.4M | 1,035,530 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Pegasystems Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $19.4M | 455,290 | 0.6% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Catalyst Pharmaceuticals, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $19.3M | 780,570 | 0.6% | |
| — | Q2 Holdings, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $18.7M | 394,629 | 0.6% | |
| — | Powell Industries Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $18.5M | 34,157 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Irhythm Holdings, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $18.4M | 156,004 | 0.5% | |
| — | Box, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $18.2M | 771,520 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Argan, Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $18.1M | 33,322 | 0.5% | |
| — | Hinge Health, Inc. · COM CUSIP 433313103 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $18.0M | 465,766 | 0.5% | |
| — | New York Times Co. Cl A · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $17.7M | 211,650 | 0.5% | |
| — | American Eagle Outfitters · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $17.4M | 1,044,900 | 0.5% | |
| — | Alighnment Healthcare, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $17.0M | 966,600 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | ANI Pharmaceuticals, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $17.0M | 221,386 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Envista Holdings Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $16.9M | 665,400 | 0.5% | |
| — | Genedx Holdings Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $16.8M | 261,370 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | SPX Technologies, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $16.7M | 83,441 | 0.5% | |
| — | Shake Shack, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $16.6M | 187,570 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Calix, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $16.4M | 335,030 | 0.5% | |
| — | Super Group SGHC Ltd. · COM CUSIP G8588X103 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $16.4M | 1,514,400 | 0.5% | |
| — | EZCorp, Inc. · COM CUSIP 302301106 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $16.2M | 639,400 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | LeMaitre Vascular, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $16.2M | 148,601 | 0.5% | |
| — | Advanced Energy Industry, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $15.9M | 49,183 | 0.5% | |
| — | Zurn Elkay Water Solutions Cor · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $15.8M | 352,183 | 0.5% | |
| — | Fabrinet · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $15.8M | 30,263 | 0.5% | |
| — | Kiniksa Pharmaceuticals, Ltd. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $15.3M | 318,634 | 0.5% | |
| — | Phibro Animal Health Corp · COM CUSIP 71742Q106 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $15.3M | 277,100 | 0.5% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Diodes, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $15.3M | 224,300 | 0.5% | |
| — | Ambarella, Inc. · COM CUSIP G037AX101 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $15.2M | 295,185 | 0.4% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Pediatrix Medical Group, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $15.0M | 701,087 | 0.4% | |
| — | Magnolia Oil & Gas Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $14.3M | 454,466 | 0.4% | |
| — | Skyward Specialty Ins Group · COM CUSIP 830940102 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $14.3M | 327,100 | 0.4% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Halozyme Therapeutics, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $14.2M | 219,930 | 0.4% | |
| — | Liquidia Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $14.0M | 372,100 | 0.4% | |
| — | Arlo Technologies, Inc. · COM CUSIP 04206A101 quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $14.0M | 982,300 | 0.4% | |
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | HealthEquity Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d | $13.9M | 166,641 | 0.4% | |
| — | ProPetro Holding Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $13.9M | 965,500 | 0.4% | |
| — | Zeta Global Holdings Corp. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $13.9M | 871,060 | 0.4% | |
| — | Mirion Technologies, Inc. · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-15 +45d ticker not yet mapped | $13.8M | 744,267 | 0.4% |
1–20 of the 100 issuers on this page
1–100 of 179 issuers · page 1 of 2
One line per issuer, largest first — open a line for its reported rows. Grouping ↗
Book shape
Tick = median of the 8,748 tracked filers with a 2026-03-31 book (the index median: the 8,662 with a complete book). Concentration uses reported 13F long value, not total assets; the index is withheld when any position lacks a value.- 41.8%below median 80.0%
- integer Herfindahl–Hirschman index in basis points over disclosed position values
- 142 bpsbelow median 446 bps
- holdings with no disclosed value (undisclosed, or unreadable on the filing) — kept and counted, never shown as zero
- 180 / 180median book 97.5 positions
201 quarter-over-quarter rows
Filing history
| Period | Source |
|---|---|
| 2026-03-31 | EDGAR ↗ |
Complete source filings on SEC EDGAR
The filing on EDGAR is the record, including any filed after this build.
Open OBERWEIS ASSET MANAGEMENT INC/'s 13F filings on SEC EDGAR ↗A 13F is a quarterly, long-only snapshot filed up to 45 days late — not current holdings. what a 13F covers ↗
13F reports cover LONG positions in Section 13(f) securities (US exchange-traded equities plus reportable options, warrants, certain convertibles) held by managers with at least $100M in such securities — so managers below that threshold are absent entirely. No short positions, no cash, no non-13(f) assets — not a full portfolio, and not a census of institutional ownership.
Positions are quarter-end snapshots filed up to 45 days late — not current holdings: a position may have changed or closed since the quarter ended.
Values are the manager's stated market value at quarter-end in era-dependent units (whole dollars for form versions effective 2023-01-03 onward, thousands before), normalized here to whole dollars; each record notes its original unit.
Affiliated managers may report the same position, so one position can appear under more than one filer.
Positions under confidential treatment may be omitted until a later amendment discloses them.
These are disclosures, not investment advice.