Portolan Capital Management, LLC — 13F Holdings & Portfolio
CIK 1350290 · latest 13F-HR filed 2026-05-15
Portolan Capital Management, LLC manages $1.88B in 13F-reported U.S. long-equity assets across 144 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are MOD (4.75%), TTMI (3.77%), CLS (2.97%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 30 new positions, exited 41, added to 50, and trimmed 57.
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.
$1.88B
Long-equity book
144
Distinct positions
2026-03-31
Filed 2026-05-15
+30 / −41 / ↑50 / ↓57
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- VIRTU FINL INC$40.8M +325.1%
- CRESCENT ENERGY COMPANY$34.8M +10389.7%
- FABRINET$23.6M +476.7%
- OKEANIS ECO TANKERS COR$21.8M +397.8%
- UNITED THERAPEUTICS CORP DEL$19.7M +110.1%
Top Trims
- CASTLE BIOSCIENCES INC-$34.1M -50.7%
- SHIFT4 PMTS INC-$20.1M -68.2%
- GENIUS SPORTS LIMITED-$20.0M -61.8%
- ZETA GLOBAL HOLDINGS CORP-$19.1M -71.2%
- QUANTERIX CORP-$18.4M -64.0%
New Positions
- PAR PAC HOLDINGS INC$43.5M
- PBF ENERGY INC$38.1M
- MURPHY USA INC$23.8M
- CIRCLE INTERNET GROUP INC$20.4M
- DHT HOLDINGS INC$19.9M
Exited Positions
- FIRST SOLAR INC$20.6M
- FIRST AMERN FINL CORP$19.7M
- SPHERE ENTERTAINMENT CO$16.7M
- MAREX GROUP PLC$16.1M
- BIO-TECHNE CORP$14.6M
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 | MODINE MFG CO | MOD | 607828100 | $89.3M | 4.75% | 412,092 | SH |
| 2 | TTM TECHNOLOGIES INC | TTMI | 87305R109 | $70.9M | 3.77% | 727,494 | SH |
| 3 | CELESTICA INC | CLS | 15101Q207 | $55.7M | 2.97% | 197,863 | SH |
| 4 | VIRTU FINL INC | VIRT | 928254101 | $53.3M | 2.84% | 1,211,887 | SH |
| 5 | AKAMAI TECHNOLOGIES INC | AKAM | 00971T101 | $48.6M | 2.59% | 423,442 | SH |
| 6 | VISHAY PRECISION GROUP INC | VPG | 92835K103 | $44.3M | 2.36% | 1,019,868 | SH |
| 7 | PAR PAC HOLDINGS INC | PARR | 69888T207 | $43.5M | 2.31% | 693,834 | SH |
| 8 | POWELL INDS INC | POWL | 739128106 | $41.0M | 2.18% | 75,830 | SH |
| 9 | BAIDU INC | BIDU | 056752108 | $40.8M | 2.17% | 366,429 | SH |
| 10 | PBF ENERGY INC | PBF | 69318G106 | $38.1M | 2.03% | 799,998 | SH |
| 11 | UNITED THERAPEUTICS CORP DEL | UTHR | 91307C102 | $37.6M | 2.00% | 63,435 | SH |
| 12 | THE REAL BROKERAGE INC | REAX | 75585H206 | $36.3M | 1.93% | 14,519,848 | SH |
| 13 | CANADA GOOSE HLDGS INC | GOOS | 135086106 | $35.3M | 1.88% | 3,218,277 | SH |
| 14 | CRESCENT ENERGY COMPANY | CRGY | 44952J104 | $35.1M | 1.87% | 2,601,142 | SH |
| 15 | CASTLE BIOSCIENCES INC | CSTL | 14843C105 | $33.1M | 1.76% | 1,350,283 | SH |
| 16 | LANTHEUS HLDGS INC | LNTH | 516544103 | $31.7M | 1.68% | 417,390 | SH |
| 17 | CELLEBRITE DI LTD | CLBT | M2197Q107 | $30.1M | 1.60% | 2,180,924 | SH |
| 18 | LUXEXPERIENCE BV | LUXE | 55406W103 | $29.9M | 1.59% | 3,733,943 | SH |
| 19 | FLEXTRONICS INTL LTD | FLEX | Y2573F102 | $29.0M | 1.54% | 443,128 | SH |
| 20 | FABRINET | FN | G3323L100 | $28.6M | 1.52% | 54,763 | SH |
| 21 | OKEANIS ECO TANKERS COR | ECO | Y64177101 | $27.3M | 1.45% | 538,860 | SH |
| 22 | TALEN ENERGY CORP | TLN | 87422Q109 | $26.0M | 1.39% | 81,574 | SH |
| 23 | SEMTECH CORP | SMTC | 816850101 | $25.6M | 1.36% | 332,327 | SH |
| 24 | CORE NATURAL RESOURCES INC | CNR | 218937100 | $24.8M | 1.32% | 237,036 | SH |
| 25 | MURPHY USA INC | MUSA | 626755102 | $23.8M | 1.26% | 48,107 | SH |
| 26 | BIOGEN INC | BIIB | 09062X103 | $21.7M | 1.16% | 118,481 | SH |
| 27 | KURA SUSHI USA INC | KRUS | 501270102 | $21.0M | 1.12% | 301,212 | SH |
| 28 | QUALYS INC | QLYS | 74758T303 | $21.0M | 1.12% | 239,028 | SH |
| 29 | JABIL INC | JBL | 466313103 | $20.5M | 1.09% | 77,197 | SH |
| 30 | CIRCLE INTERNET GROUP INC | CRCL | 172573107 | $20.4M | 1.09% | 213,796 | SH |
| 31 | DHT HOLDINGS INC | DHT | Y2065G121 | $19.9M | 1.06% | 1,091,788 | SH |
| 32 | NOKIA CORP | NOK | 654902204 | $19.2M | 1.02% | 2,393,970 | SH |
| 33 | ALLIENT INC | ALNT | 019330109 | $19.1M | 1.02% | 323,453 | SH |
| 34 | PRIMORIS SVCS CORP | PRIM | 74164F103 | $18.7M | 0.99% | 130,626 | SH |
| 35 | DAVE INC | DAVE | 23834J201 | $18.4M | 0.98% | 105,442 | SH |
| 36 | KRATOS DEFENSE & SEC SOLUTIO | KTOS | 50077B207 | $18.3M | 0.97% | 259,811 | SH |
| 37 | MAMAS CREATIONS INC | MAMA | 56146T103 | $18.1M | 0.96% | 1,176,936 | SH |
| 38 | ADEIA INC | ADEA | 00676P107 | $17.5M | 0.93% | 729,461 | SH |
| 39 | UPWORK INC | UPWK | 91688F104 | $17.2M | 0.92% | 1,570,560 | SH |
| 40 | PULSE BIOSCIENCES INC | PLSE | 74587B101 | $15.8M | 0.84% | 733,372 | SH |
| 41 | PORCH GROUP INC | PRCH | 733245104 | $15.4M | 0.82% | 2,144,890 | SH |
| 42 | HAFNIA LTD | HAFN | Y2990R101 | $14.8M | 0.79% | 1,948,717 | SH |
| 43 | MAYVILLE ENGR CO INC | MEC | 578605107 | $14.7M | 0.78% | 821,136 | SH |
| 44 | CANDEL THERAPEUTICS INC | CADL | 137404109 | $14.2M | 0.75% | 2,894,325 | SH |
| 45 | NLIGHT INC | LASR | 65487K100 | $12.9M | 0.68% | 225,576 | SH |
| 46 | GENIUS SPORTS LIMITED | GENI | G3934V109 | $12.4M | 0.66% | 2,791,018 | SH |
| 47 | AMER SPORTS INC | AS | G0260P102 | $11.8M | 0.63% | 357,826 | SH |
| 48 | EBAY INC. | EBAY | 278642103 | $11.5M | 0.61% | 126,096 | SH |
| 49 | PARK AEROSPACE CORP | PKE | 70014A104 | $11.2M | 0.60% | 410,655 | SH |
| 50 | ENOVA INTL INC | ENVA | 29357K103 | $11.0M | 0.58% | 80,923 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-15 | $1.88B | 144 | 0001104659-26-062488 |
| 2025-12-31 | 2026-02-17 | $1.87B | 155 | 0001104659-26-016304 |
| 2025-09-30 | 2025-11-13 | $1.85B | 119 | 0001104659-25-111284 |