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

0$1.0B$2.0B$3.0B Q1 2024: $1.3B Q1 2024 Q2 2024: $1.2B Q2 2024 Q3 2024: $1.4B Q3 2024 Q4 2024: $1.5B Q4 2024 Q1 2025: $1.3B Q1 2025 Q2 2025: $1.6B Q2 2025 Q3 2025: $1.8B Q3 2025 Q4 2025: $1.9B Q4 2025 Q1 2026: $1.9B $1.9B Q1 2026 Q2 2026: $2.7B Q2 2026

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%
PSNL Personalis Inc. 0.25% 736,713 $4.7M Add +94.3%
MBLY Mobileye Global Inc. Class A 0.25% 678,135 $4.7M Add +98.3%
IIIV I3 Verticals Inc. Class A 0.25% 207,274 $4.6M Reduce -69.2%
ONTO Onto Innovation Inc. 0.24% 22,263 $4.6M New
PUMP Propetro Holding Corp. 0.24% 314,815 $4.5M New
SEZL Sezzle Inc. 0.24% 70,046 $4.4M Reduce -58.3%
NOVT Novanta Inc. 0.24% 37,507 $4.4M Reduce -65.0%
DOUG Douglas Elliman Inc. 0.23% 2,669,030 $4.4M Add +13.4%
VICR Vicor Corp. 0.23% 26,670 $4.3M Reduce -45.3%
LITE Lumentum Holdings Inc. 0.22% 5,822 $4.1M No change
BIO Bio-Rad Laboratories-A 0.21% 14,173 $4.0M Reduce -58.5%
SANM Sanmina Corp. 0.19% 27,332 $3.5M Reduce -59.0%
FPS Forgent Power Solutions Class A 0.18% 117,933 $3.5M New
DPRO Draganfly Inc. 0.18% 682,730 $3.4M New
GDOT Green Dot Corp. Class A 0.18% 298,697 $3.4M Reduce -26.6%
ACMR Acm Research Inc. Class A 0.17% 83,256 $3.3M Reduce -70.8%
SPT Sprout Social Inc. Class A 0.17% 558,350 $3.2M Add +85.2%
XZO Exzeo Group Inc. 0.16% 209,885 $3.1M Reduce -48.2%
OSK Oshkosh Corp. 0.14% 18,185 $2.7M Reduce -29.9%
AAOI Applied Optoelectronics Inc. 0.13% 29,833 $2.5M Reduce -86.9%
AMPL Amplitude Inc. Class A 0.13% 359,593 $2.5M Reduce -35.8%
TPR Tapestry Inc. 0.13% 17,038 $2.4M Reduce -34.1%
GCT Gigacloud Technology Inc. Class A 0.13% 52,014 $2.4M Reduce -62.2%
NTRA Natera Inc. 0.12% 11,418 $2.3M Reduce -26.8%
UCTT Ultra Clean Holdings Inc. 0.11% 33,700 $2.1M New
SD Sandridge Energy Inc. 0.11% 123,591 $2.0M Reduce -7.8%
FLGT Fulgent Genetics Inc. 0.09% 106,642 $1.7M Reduce -37.1%
KOS Kosmos Energy Ltd. 0.09% 602,542 $1.7M New
GOOG Alphabet Inc. Class C 0.09% 5,710 $1.6M Reduce -18.3%
SEI Solaris Energy Infrastructur 0.08% 27,930 $1.6M Add +43.4%
RDNT Radnet Inc. 0.07% 23,728 $1.3M Reduce -79.8%
PL Planet Labs PBC 0.07% 47,288 $1.3M Reduce -31.2%
GH Guardant Health Inc. 0.07% 14,155 $1.3M Reduce -86.4%
CWST Casella Waste Systems Inc. Class A 0.06% 15,100 $1.2M Reduce -0.8%
DAN Dana Inc. 0.06% 34,237 $1.2M Reduce -86.4%
TGEN Tecogen Inc./Waltham Ma 0.06% 443,555 $1.1M Reduce -0.5%
TMDX Transmedics Group Inc. 0.06% 10,688 $1.1M Reduce -89.0%
ECG Everus Construction Group 0.05% 8,725 $1.0M No change
LHX L3HARRIS Technologies Inc. 0.04% 2,157 $744K No change
GDS GDS Holdings Ltd. - ADR filed as GDS HLDGS LTD 0.03% 15,281 $616K Reduce -0.5%
HUCK Huckleberry AI Inc. filed as DOMO INC 0.03% 197,104 $603K Reduce -90.9%
LINC Lincoln Educational Services 0.03% 14,007 $570K No change
ESTA Establishment Labs Holdings 0.03% 9,573 $544K Reduce -89.9%
AMPY Amplify Energy Corp. 0.02% 74,120 $463K Reduce -16.8%

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

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 148$2.7BVPG, VIRT, TTMI, MOD, QLYS
Q1 2026 144$1.9BMOD, TTMI, CLS, VIRT, AKAM
Q4 2025 155$1.9BTTMI, MOD, CSTL, CLS, AKAM
Q3 2025 119$1.8BMOD, TTMI, ELF, DBRG, CLS
Q2 2025 118$1.6BCLS, KTOS, ELF, AVAV, MOD
Q1 2025 109$1.3BLNTH, SLM, KTOS, GENI, MOD
Q4 2024 131$1.5BLNTH, CLS, SMTC, MOD, HNST
Q3 2024 129$1.4BLNTH, ZETA, KTOS, TLN, CLS
Q2 2024 117$1.2BLNTH, CLS, SMCI, ZETA, KTOS
Q1 2024 116$1.3BSMCI, CLS, LNTH, ELF, BIO