Portolan Capital Management, LLC — 13F Holdings & Portfolio

CIK 1350290 · latest 13F-HR filed 2026-08-14

Portolan Capital Management, LLC manages $2.67B in 13F-reported U.S. long-equity assets across 148 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are VPG (5.66%), VIRT (4.78%), TTMI (3.56%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 36 new positions, exited 32, added to 62, and trimmed 39.

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.

Filer Information
Address
2 INTERNATIONAL PLACE, 26TH FLOOR
BOSTON, MA 02110
Phone
(617) 753-6400
Filing Manager
Portolan Capital Management, LLC
BOSTON, MA
Signatory
Betsy Flaherty
Chief Compliance Officer
Loading holdings…
AUM

$2.67B

Long-equity book

Holdings

148

Distinct positions

Period

2026-06-30

Filed 2026-08-14

Q/Q Activity

+36 / −32 / ↑62 / ↓39

vs 2026-03-31

Firm Profile & Key People
Name Title / Status Ownership Type

Top Adds (vs prior quarter)

  • VISHAY PRECISION GROUP INC$106.9M +241.3%
  • VIRTU FINL INC$74.3M +139.4%
  • QUALYS INC$51.8M +246.9%
  • SHIFT4 PMTS INC$44.8M +478.3%
  • ENOVA INTL INC$36.9M +335.4%
Show all 62 →

Top Trims

  • BAIDU INC-$29.9M -73.2%
  • CASTLE BIOSCIENCES INC-$25.3M -76.3%
  • FABRINET-$25.0M -87.4%
  • PAR PAC HOLDINGS INC-$24.3M -55.9%
  • OKEANIS ECO TANKERS COR-$17.4M -64.0%
Show all 39 →

New Positions

  • PENGUIN SOLUTIONS INC$41.5M
  • SPORTRADAR GROUP AG$27.2M
  • BANDWIDTH INC$26.1M
  • KONTOOR BRANDS INC$24.3M
  • ENCORE CAP GROUP INC$23.9M
Show all 36 →

Exited Positions

  • PBF ENERGY INC$38.1M
  • CRESCENT ENERGY COMPANY$35.1M
  • CORE NATURAL RESOURCES INC$24.8M
  • MURPHY USA INC$23.8M
  • CIRCLE INTERNET GROUP INC$20.4M
Show all 32 →
All Holdings

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 VISHAY PRECISION GROUP INC VPG 92835K103 $151.1M 5.66% 1,008,167 SH
2 VIRTU FINL INC VIRT 928254101 $127.6M 4.78% 2,142,215 SH
3 TTM TECHNOLOGIES INC TTMI 87305R109 $95.0M 3.56% 507,838 SH
4 MODINE MFG CO MOD 607828100 $83.8M 3.14% 313,683 SH
5 QUALYS INC QLYS 74758T303 $72.8M 2.73% 529,807 SH
6 SHIFT4 PMTS INC FOUR 82452J109 $54.2M 2.03% 1,114,116 SH
7 MAYVILLE ENGR CO INC MEC 578605107 $48.7M 1.82% 1,299,256 SH
8 ENOVA INTL INC ENVA 29357K103 $47.9M 1.79% 198,795 SH
9 SEMTECH CORP SMTC 816850101 $47.7M 1.79% 294,619 SH
10 CELESTICA INC CLS 15101Q207 $46.3M 1.73% 126,856 SH
11 UNITED THERAPEUTICS CORP DEL UTHR 91307C102 $44.2M 1.65% 81,518 SH
12 GENIUS SPORTS LIMITED GENI G3934V109 $42.6M 1.59% 7,025,809 SH
13 POWELL INDS INC POWL 739128106 $41.7M 1.56% 145,631 SH
14 PENGUIN SOLUTIONS INC PENG 706915105 $41.5M 1.55% 546,173 SH
15 DAVE INC DAVE 23834J201 $39.2M 1.47% 105,338 SH
16 FLEX LTD FLEX Y2573F102 $37.1M 1.39% 229,027 SH
17 ALLIENT INC ALNT 019330109 $37.0M 1.39% 359,685 SH
18 PORCH GROUP INC PRCH 733245104 $36.9M 1.38% 2,456,451 SH
19 AKAMAI TECHNOLOGIES INC AKAM 00971T101 $36.7M 1.37% 310,361 SH
20 CANDEL THERAPEUTICS INC CADL 137404109 $36.0M 1.35% 3,490,398 SH
21 TALEN ENERGY CORP TLN 87422Q109 $34.7M 1.30% 90,312 SH
22 REGAL REXNORD CORPORATION RRX 758750103 $32.8M 1.23% 137,498 SH
23 LANTHEUS HLDGS INC LNTH 516544103 $32.0M 1.20% 288,691 SH
24 BIOGEN INC BIIB 09062X103 $30.9M 1.16% 142,856 SH
25 VEECO INSTRS INC DEL VECO 922417100 $30.4M 1.14% 401,639 SH
26 LUXEXPERIENCE BV LUXE 55406W103 $30.1M 1.13% 4,053,147 SH
27 ZETA GLOBAL HOLDINGS CORP ZETA 98956A105 $29.6M 1.11% 1,502,738 SH
28 CELLEBRITE DI LTD CLBT M2197Q107 $28.2M 1.06% 1,932,514 SH
29 SPORTRADAR GROUP AG SRAD H8088L103 $27.2M 1.02% 1,819,949 SH
30 CANADA GOOSE HLDGS INC GOOS 135086106 $26.2M 0.98% 2,750,523 SH
31 BANDWIDTH INC BAND 05988J103 $26.1M 0.98% 412,701 SH
32 WARBY PARKER INC WRBY 93403J106 $25.6M 0.96% 843,862 SH
33 KONTOOR BRANDS INC KTB 50050N103 $24.3M 0.91% 292,115 SH
34 OSHKOSH CORP OSK 688239201 $24.2M 0.91% 157,641 SH
35 ENCORE CAP GROUP INC ECPG 292554102 $23.9M 0.89% 255,715 SH
36 TWILIO INC TWLO 90138F102 $23.8M 0.89% 115,397 SH
37 SEZZLE INC SEZL 78435P105 $23.3M 0.87% 135,743 SH
38 REMITLY GLOBAL INC RELY 75960P104 $22.8M 0.85% 1,017,592 SH
39 ACM RESH INC ACMR 00108J109 $22.5M 0.84% 177,432 SH
40 ELEMENT SOLUTIONS INC ESI 28618M106 $22.4M 0.84% 469,213 SH
41 NOKIA CORP NOK 654902204 $21.9M 0.82% 1,645,761 SH
42 BLACKBERRY LTD BB 09228F103 $21.7M 0.81% 1,714,461 SH
43 INTERNATIONAL FLAVORS&FRAGRA IFF 459506101 $21.3M 0.80% 269,229 SH
44 PULSE BIOSCIENCES INC PLSE 74587B101 $20.9M 0.78% 753,333 SH
45 MOOG INC MOG.A 615394202 $20.9M 0.78% 49,274 SH
46 THE REAL BROKERAGE INC REAX 75585H206 $20.1M 0.75% 11,042,364 SH
47 CAREDX INC CDNA 14167L103 $19.5M 0.73% 684,805 SH
48 PAR PAC HOLDINGS INC PARR 69888T207 $19.2M 0.72% 341,863 SH
49 VISHAY INTERTECHNOLOGY INC VSH 928298108 $18.9M 0.71% 351,515 SH
50 TAKE-TWO INTERACTIVE SOFTWAR TTWO 874054109 $18.1M 0.68% 72,487 SH
Filing History
Period Filed AUM Holdings Accession
2026-06-30 2026-08-14 $2.67B 148 0001104659-26-096980
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