Portolan Capital Management, LLC
In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 15, 2026), Portolan Capital Management, LLC reported 144 stock positions worth $1.9 billion. Its top holding was Modine Manufacturing (MOD) at 4.8% of the portfolio, followed by TTM Technologies (TTMI, 3.8%) and Celestica (CLS, 3.0%). Compared with Q4 2025, it opened 30 new positions, sold out of 41, added to 49 and reduced 61. The biggest buy was a new position in Par Pacific (PARR) and the biggest sale Castle Biosciences (CSTL, shares −22%).
- Most Recent 13F
- Q2 2026
- Location
- BOSTON, MA
- CIK
- 0001350290
- Portfolio Value
- $1.9B (Q1 2026)
- SEC Filing
- 0001104659-26-062488 ↗ filed May 15, 2026
Holdings Value
Holdings 144 stocks · $1.9B
| MOD Modine Manufacturing Co. | 4.75% | 412,092 | $89.3M | Reduce -23.1% |
| TTMI TTM Technologies | 3.77% | 727,494 | $70.9M | Reduce -36.6% |
| CLS Celestica Inc. | 2.97% | 197,863 | $55.7M | Add +14.8% |
| VIRT Virtu Financial Inc. Class A | 2.84% | 1,211,887 | $53.3M | Add +222.1% |
| AKAM Akamai Technologies Inc. | 2.59% | 423,442 | $48.6M | Reduce -19.2% |
| VPG Vishay Precision Group | 2.36% | 1,019,868 | $44.3M | Add +16.2% |
| PARR Par Pacific Holdings Inc. | 2.31% | 693,834 | $43.5M | New |
| POWL Powell Industries Inc. | 2.18% | 75,830 | $41.0M | Reduce -4.2% |
| BIDU Baidu Inc. - Spon ADR | 2.17% | 366,429 | $40.8M | Add +39.0% |
| PBF PBF Energy Inc. Class A | 2.03% | 799,998 | $38.1M | New |
| UTHR United Therapeutics Corp. | 2.00% | 63,435 | $37.6M | Add +72.6% |
| REAL BROKERAGE INC/THE filed as THE REAL BROKERAGE INC | 1.93% | 14,519,848 | $36.3M | Add +34.7% |
| GOOS Canada Goose Holdings Inc. | 1.88% | 3,218,277 | $35.3M | Add +50.5% |
| CRGY Crescent Energy Inc. Class A | 1.87% | 2,601,142 | $35.1M | Add +6419.1% |
| CSTL Castle Biosciences Inc. | 1.76% | 1,350,283 | $33.1M | Reduce -21.9% |
| LNTH Lantheus Holdings Inc. | 1.68% | 417,390 | $31.7M | Reduce -12.3% |
| CLBT Cellebrite Di Ltd. | 1.60% | 2,180,924 | $30.1M | Add +69.4% |
| LUXE Luxexperience BV | 1.59% | 3,733,943 | $29.9M | Add +40.3% |
| FLEX Flex Ltd. filed as FLEXTRONICS INTL LTD | 1.54% | 443,128 | $29.0M | Reduce -5.1% |
| FN Fabrinet | 1.52% | 54,763 | $28.6M | Add +403.4% |
| ECO Okeanis Eco Tankers Corp. | 1.45% | 538,860 | $27.3M | Add +233.0% |
| TLN Talen Energy Corp. | 1.39% | 81,574 | $26.0M | Add +8.8% |
| SMTC Semtech Corp. | 1.36% | 332,327 | $25.6M | Reduce -34.7% |
| CNR Core Natural Resources Inc. | 1.32% | 237,036 | $24.8M | Add +82.0% |
| MUSA Murphy USA Inc. | 1.26% | 48,107 | $23.8M | New |
| BIIB Biogen Inc. | 1.16% | 118,481 | $21.7M | Add +39.4% |
| KRUS Kura Sushi USA Inc. Class A | 1.12% | 301,212 | $21.0M | Add +57.9% |
| QLYS Qualys Inc. | 1.12% | 239,028 | $21.0M | Add +360.9% |
| JBL Jabil Inc. | 1.09% | 77,197 | $20.5M | Add +9.2% |
| CRCL Circle Internet Group Inc. | 1.09% | 213,796 | $20.4M | New |
| DHT DHT Holdings Inc. | 1.06% | 1,091,788 | $19.9M | New |
| NOK Nokia Corp.-Spon ADR | 1.02% | 2,393,970 | $19.2M | Add +122.5% |
| ALNT Allient Inc. | 1.02% | 323,453 | $19.1M | Add +7.1% |
| PRIM Primoris Services Corp. | 0.99% | 130,626 | $18.7M | Add +23.6% |
| DAVE Dave Inc. | 0.98% | 105,442 | $18.4M | Add +139.6% |
| KTOS Kratos Defense & Security | 0.97% | 259,811 | $18.3M | Reduce -11.6% |
| MAMA Mama's Creations Inc. | 0.96% | 1,176,936 | $18.1M | Reduce -5.5% |
| ADEA Adeia Inc. | 0.93% | 729,461 | $17.5M | Add +184.7% |
| UPWK Upwork Inc. | 0.92% | 1,570,560 | $17.2M | Add +118.2% |
| PLSE Pulse Biosciences Inc. | 0.84% | 733,372 | $15.8M | Add +86.4% |
| PRCH Porch Group Inc. | 0.82% | 2,144,890 | $15.4M | Add +3.0% |
| HAFN Hafnia Ltd. | 0.79% | 1,948,717 | $14.8M | New |
| MEC Mayville Engineering Co. Inc. | 0.78% | 821,136 | $14.7M | Add +60.1% |
| CADL Candel Therapeutics Inc. | 0.75% | 2,894,325 | $14.2M | Add +70.7% |
| LASR Nlight Inc. | 0.68% | 225,576 | $12.9M | Reduce -61.8% |
| GENI Genius Sports Ltd. | 0.66% | 2,791,018 | $12.4M | Reduce -5.0% |
| AS Amer Sports Inc. | 0.63% | 357,826 | $11.8M | New |
| EBAY eBay Inc. | 0.61% | 126,096 | $11.5M | Add +116.9% |
| PKE Park Aerospace Corp. | 0.60% | 410,655 | $11.2M | Add +67.6% |
| ENVA Enova International Inc. | 0.58% | 80,923 | $11.0M | Reduce -17.3% |
| RELY Remitly Global Inc. | 0.58% | 698,166 | $10.9M | Add +11.2% |
| EVLV Evolv Technologies Holdings | 0.58% | 1,795,688 | $10.9M | New |
| WRBY Warby Parker Inc. Class A | 0.56% | 500,706 | $10.5M | Reduce -59.4% |
| BELFB Bel Fuse Inc. Class B | 0.56% | 53,170 | $10.5M | Reduce -61.9% |
| LPTH Lightpath Technologies Inc. Class A | 0.56% | 1,040,462 | $10.4M | Reduce -55.4% |
| QTRX Quanterix Corp. | 0.55% | 2,945,823 | $10.4M | Reduce -34.9% |
| RRX Regal Rexnord Corp. | 0.54% | 53,975 | $10.1M | Add +133.7% |
| AMSC American Superconductor Corp. | 0.53% | 295,636 | $10.0M | New |
| TWLO Twilio Inc. Class A | 0.50% | 74,769 | $9.4M | New |
| FOUR SHIFT4 Payments Inc. Class A | 0.50% | 214,284 | $9.4M | Reduce -54.2% |
| HNST The Honest Co. Inc. | 0.48% | 3,045,834 | $9.0M | Reduce -36.6% |
| FORR Forrester Research Inc. | 0.46% | 1,541,276 | $8.7M | Add +118.4% |
| LPRO Open Lending Corp. | 0.46% | 6,902,888 | $8.6M | Add +45.7% |
| MOG.A Moog Inc. Class A | 0.46% | 29,437 | $8.6M | New |
| VECO Veeco Instruments Inc. | 0.46% | 253,379 | $8.6M | New |
| HQY Healthequity Inc. | 0.45% | 101,646 | $8.5M | New |
| ELF Elf Beauty Inc. | 0.44% | 136,707 | $8.3M | Reduce -28.9% |
| DGII Digi International Inc. | 0.44% | 170,256 | $8.2M | Reduce -28.3% |
| GHM Graham Corp. | 0.43% | 103,556 | $8.2M | New |
| ZETA Zeta Global Holdings Corp. Class A | 0.41% | 486,271 | $7.7M | Reduce -63.1% |
| ESI Element Solutions Inc. | 0.40% | 221,232 | $7.6M | New |
| RPAY Repay Holdings Corp. | 0.40% | 2,856,178 | $7.4M | Add +2.4% |
| ZGN Ermenegildo Zegna NV | 0.39% | 710,626 | $7.4M | Add +0.0% |
| WLDN Willdan Group Inc. | 0.38% | 93,964 | $7.2M | Add +63.1% |
| ACLS Axcelis Technologies Inc. | 0.38% | 77,168 | $7.2M | New |
| CIEN Ciena Corp. | 0.38% | 18,466 | $7.2M | Reduce -67.3% |
| PACK Ranpak Holdings Corp. | 0.37% | 1,947,681 | $7.0M | Reduce -0.2% |
| VNET Vnet Group Inc.-ADR | 0.37% | 825,490 | $6.9M | Add +2.3% |
| ONON On Holding AG Class A filed as ON HLDG AG | 0.37% | 202,444 | $6.9M | New |
| NXT Nextpower Inc. | 0.36% | 56,747 | $6.8M | Reduce -28.9% |
| FEIM Frequency Electronics Inc. | 0.35% | 150,141 | $6.6M | Add +32.8% |
| WGS Genedx Holdings Corp. | 0.35% | 102,575 | $6.6M | Add +83.9% |
| TTWO Take-Two Interactive Softwre | 0.34% | 32,219 | $6.4M | Reduce -14.5% |
| PRCT Procept Biorobotics Corp. | 0.34% | 251,716 | $6.3M | Reduce -1.3% |
| NOG Northern Oil and Gas Inc. | 0.32% | 204,244 | $6.0M | New |
| CDNA Caredx Inc. | 0.31% | 340,352 | $5.9M | Reduce -55.1% |
| BL Blackline Inc. | 0.31% | 159,026 | $5.9M | New |
| META Meta Platforms Inc. Class A | 0.31% | 10,261 | $5.9M | Reduce -0.6% |
| CELH Celsius Holdings Inc. | 0.31% | 164,597 | $5.8M | New |
| DBRG Digitalbridge Group Inc. | 0.31% | 373,130 | $5.8M | Reduce -54.8% |
| IESC Ies Holdings Inc. | 0.30% | 11,869 | $5.7M | Add +0.7% |
| TSEM Tower Semiconductor Ltd. | 0.30% | 32,043 | $5.6M | Reduce -78.4% |
| AMBA Ambarella Inc. | 0.30% | 108,749 | $5.6M | Add +100.5% |
| CENX Century Aluminum Company | 0.30% | 95,039 | $5.6M | New |
| TALO Talos Energy Inc. | 0.29% | 344,549 | $5.4M | Add +189.3% |
| TLX Telix Pharmaceuticals Ltd. | 0.28% | 541,267 | $5.2M | New |
| MIAX Miami International Holdings | 0.27% | 128,819 | $5.0M | New |
| AVAV Aerovironment Inc. | 0.26% | 26,880 | $4.9M | Reduce -64.6% |
| VIAV Viavi Solutions Inc. | 0.26% | 145,844 | $4.9M | New |
| XPEV Xpeng Inc. - ADR | 0.25% | 275,432 | $4.7M | Add +184.2% |
Portfolio Sells Q4 2025 → Q1 2026
| CSTL Castle Biosciences Inc. | Reduce -21.9% | 1.76% | −1.84 |
| FSLR First Solar Inc. | Sold out | 0.00% | −1.10 |
| FOUR SHIFT4 Payments Inc. Class A | Reduce -54.2% | 0.50% | −1.08 |
| GENI Genius Sports Ltd. | Reduce -5.0% | 0.66% | −1.08 |
| FAF First American Financial | Sold out | 0.00% | −1.06 |
| ZETA Zeta Global Holdings Corp. Class A | Reduce -63.1% | 0.41% | −1.03 |
| QTRX Quanterix Corp. | Reduce -34.9% | 0.55% | −0.99 |
| HUCK Huckleberry AI Inc. | Reduce -90.9% | 0.03% | −0.94 |
| SPHR Sphere Entertainment Co. | Sold out | 0.00% | −0.89 |
| WRBY Warby Parker Inc. Class A | Reduce -59.4% | 0.56% | −0.88 |
| MRX Marex UK Holdings Ltd. | Sold out | 0.00% | −0.86 |
| LPTH Lightpath Technologies Inc. Class A | Reduce -55.4% | 0.56% | −0.79 |
| TECH Bio-Techne Corp. | Sold out | 0.00% | −0.78 |
| FCX Freeport-McMoran Inc. | Sold out | 0.00% | −0.78 |
| MGA Magna International Inc. | Sold out | 0.00% | −0.73 |
| AVAV Aerovironment Inc. | Reduce -64.6% | 0.26% | −0.72 |
| BELFB Bel Fuse Inc. Class B | Reduce -61.9% | 0.56% | −0.71 |
| IIIV I3 Verticals Inc. Class A | Reduce -69.2% | 0.25% | −0.66 |
| SMTC Semtech Corp. | Reduce -34.7% | 1.36% | −0.65 |
| SNAP Snap Inc. Class A | Sold out | 0.00% | −0.65 |
| TGLS Tecnoglass Holdings Inc. | Sold out | 0.00% | −0.64 |
| TSEM Tower Semiconductor Ltd. | Reduce -78.4% | 0.30% | −0.64 |
| HZO Marinemax Inc. | Sold out | 0.00% | −0.63 |
| TMDX Transmedics Group Inc. | Reduce -89.0% | 0.06% | −0.57 |
| ZG Zillow Group Inc. Class A | Sold out | 0.00% | −0.55 |
| METC Ramaco Resources Inc. Class A | Sold out | 0.00% | −0.54 |
| LASR Nlight Inc. | Reduce -61.8% | 0.68% | −0.50 |
| GH Guardant Health Inc. | Reduce -86.4% | 0.07% | −0.50 |
| OPRA Opera Ltd.-ADR | Sold out | 0.00% | −0.48 |
| TTMI TTM Technologies | Reduce -36.6% | 3.77% | −0.47 |
| WAT Waters Corp. | Sold out | 0.00% | −0.46 |
| CDNA Caredx Inc. | Reduce -55.1% | 0.31% | −0.45 |
| NOVT Novanta Inc. | Reduce -65.0% | 0.24% | −0.45 |
| WIX Wix.com Ltd. | Sold out | 0.00% | −0.45 |
| STC Stewart Information Services | Sold out | 0.00% | −0.44 |
| ACMR Acm Research Inc. Class A | Reduce -70.8% | 0.17% | −0.43 |
| RDNT Radnet Inc. | Reduce -79.8% | 0.07% | −0.38 |
| DBRG Digitalbridge Group Inc. | Reduce -54.8% | 0.31% | −0.37 |
| XZO Exzeo Group Inc. | Reduce -48.2% | 0.16% | −0.36 |
| SANM Sanmina Corp. | Reduce -59.0% | 0.19% | −0.35 |
| BIO Bio-Rad Laboratories-A | Reduce -58.5% | 0.21% | −0.34 |
| ELF Elf Beauty Inc. | Reduce -28.9% | 0.44% | −0.34 |
| ESTA Establishment Labs Holdings | Reduce -89.9% | 0.03% | −0.34 |
| DKNG Draftkings Inc. Class A | Sold out | 0.00% | −0.34 |
| SEZL Sezzle Inc. | Reduce -58.3% | 0.24% | −0.34 |
| CIEN Ciena Corp. | Reduce -67.3% | 0.38% | −0.33 |
| NUS Nu Skin Enterprises Inc. Class A | Sold out | 0.00% | −0.31 |
| SG Sweetgreen Inc. Class A | Sold out | 0.00% | −0.31 |
| OWLT Owlet Inc. | Sold out | 0.00% | −0.30 |
| AAOI Applied Optoelectronics Inc. | Reduce -86.9% | 0.13% | −0.29 |
Portfolio Buys Q4 2025 → Q1 2026
| PARR Par Pacific Holdings Inc. | New | 2.31% | +2.31 |
| VIRT Virtu Financial Inc. Class A | Add +222.1% | 2.84% | +2.16 |
| PBF PBF Energy Inc. Class A | New | 2.03% | +2.03 |
| CRGY Crescent Energy Inc. Class A | Add +6419.1% | 1.87% | +1.85 |
| MUSA Murphy USA Inc. | New | 1.26% | +1.26 |
| FN Fabrinet | Add +403.4% | 1.52% | +1.25 |
| ECO Okeanis Eco Tankers Corp. | Add +233.0% | 1.45% | +1.16 |
| CRCL Circle Internet Group Inc. | New | 1.09% | +1.09 |
| DHT DHT Holdings Inc. | New | 1.06% | +1.06 |
| UTHR United Therapeutics Corp. | Add +72.6% | 2.00% | +1.04 |
| HAFN Hafnia Ltd. | New | 0.79% | +0.79 |
| QLYS Qualys Inc. | Add +360.9% | 1.12% | +0.75 |
| CNR Core Natural Resources Inc. | Add +82.0% | 1.32% | +0.70 |
| ADEA Adeia Inc. | Add +184.7% | 0.93% | +0.70 |
| NOK Nokia Corp.-Spon ADR | Add +122.5% | 1.02% | +0.65 |
| AS Amer Sports Inc. | New | 0.63% | +0.63 |
| KRUS Kura Sushi USA Inc. Class A | Add +57.9% | 1.12% | +0.58 |
| EVLV Evolv Technologies Holdings | New | 0.58% | +0.58 |
| PLSE Pulse Biosciences Inc. | Add +86.4% | 0.84% | +0.55 |
| VPG Vishay Precision Group | Add +16.2% | 2.36% | +0.55 |
| AMSC American Superconductor Corp. | New | 0.53% | +0.53 |
| TWLO Twilio Inc. Class A | New | 0.50% | +0.50 |
| MOG.A Moog Inc. Class A | New | 0.46% | +0.46 |
| VECO Veeco Instruments Inc. | New | 0.46% | +0.46 |
| DAVE Dave Inc. | Add +139.6% | 0.98% | +0.46 |
| HQY Healthequity Inc. | New | 0.45% | +0.45 |
| GHM Graham Corp. | New | 0.43% | +0.43 |
| ESI Element Solutions Inc. | New | 0.40% | +0.40 |
| LUXE Luxexperience BV | Add +40.3% | 1.59% | +0.40 |
| GOOS Canada Goose Holdings Inc. | Add +50.5% | 1.88% | +0.39 |
| ACLS Axcelis Technologies Inc. | New | 0.38% | +0.38 |
| ONON On Holding AG Class A | New | 0.37% | +0.37 |
| RRX Regal Rexnord Corp. | Add +133.7% | 0.54% | +0.36 |
| CLBT Cellebrite Di Ltd. | Add +69.4% | 1.60% | +0.36 |
| BIIB Biogen Inc. | Add +39.4% | 1.16% | +0.35 |
| EBAY eBay Inc. | Add +116.9% | 0.61% | +0.34 |
| BIDU Baidu Inc. - Spon ADR | Add +39.0% | 2.17% | +0.33 |
| PKE Park Aerospace Corp. | Add +67.6% | 0.60% | +0.32 |
| NOG Northern Oil and Gas Inc. | New | 0.32% | +0.32 |
| BL Blackline Inc. | New | 0.31% | +0.31 |
| CELH Celsius Holdings Inc. | New | 0.31% | +0.31 |
| CENX Century Aluminum Company | New | 0.30% | +0.30 |
| PRIM Primoris Services Corp. | Add +23.6% | 0.99% | +0.29 |
| TLX Telix Pharmaceuticals Ltd. | New | 0.28% | +0.28 |
| MEC Mayville Engineering Co. Inc. | Add +60.1% | 0.78% | +0.27 |
| MIAX Miami International Holdings | New | 0.27% | +0.27 |
| VIAV Viavi Solutions Inc. | New | 0.26% | +0.26 |
| ONTO Onto Innovation Inc. | New | 0.24% | +0.24 |
| CADL Candel Therapeutics Inc. | Add +70.7% | 0.75% | +0.24 |
| PUMP Propetro Holding Corp. | New | 0.24% | +0.24 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 148 | $2.7B | VPG, VIRT, TTMI, MOD, QLYS |
| Q1 2026 | 144 | $1.9B | MOD, TTMI, CLS, VIRT, AKAM |
| Q4 2025 | 155 | $1.9B | TTMI, MOD, CSTL, CLS, AKAM |
| Q3 2025 | 119 | $1.8B | MOD, TTMI, ELF, DBRG, CLS |
| Q2 2025 | 118 | $1.6B | CLS, KTOS, ELF, AVAV, MOD |
| Q1 2025 | 109 | $1.3B | LNTH, SLM, KTOS, GENI, MOD |
| Q4 2024 | 131 | $1.5B | LNTH, CLS, SMTC, MOD, HNST |
| Q3 2024 | 129 | $1.4B | LNTH, ZETA, KTOS, TLN, CLS |
| Q2 2024 | 117 | $1.2B | LNTH, CLS, SMCI, ZETA, KTOS |
| Q1 2024 | 116 | $1.3B | SMCI, CLS, LNTH, ELF, BIO |