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Livermore
Livermore
ZHEN

Portolan Capital Management, LLC

SEC CIK
0001350290
Latest filing
Aug 14, 2026

The latest 13F from Portolan Capital Management, LLC covers Q2 2026 (filed Aug 14, 2026): 148 long positions worth $2.67B. The top 10 holdings make up 29.0% of the portfolio, and the largest is Vishay Precision Group, Inc. (VPG) at 5.7%. Livermore has 22 filings on Form 13F from this institution, going back to Q1 2021.

What changed in Q2 2026

Share counts compared with Q1 2026: how many positions were new, added to, reduced or sold out, and the biggest buys and sells. Dollar amounts are estimated at the quarter-end prices implied by the filing.

Full comparison
New
36
Est. +$444.3M
Added
49
Est. +$493.9M
Reduced
59
Est. −$504.2M
Sold out
32
Est. −$272.8M

Top 5 holdings

Share of this quarter's portfolio value

  1. VPGVishay Precision Group, Inc.
    5.7%$151.1MHistory
  2. VIRTVirtu Financial, Inc.
    4.8%$127.6MHistory
  3. TTMITTM Technologies Inc
    3.6%$95.0MHistory
  4. MODModine Manufacturing Co
    3.1%$83.8MHistory
  5. QLYSQualys, Inc.
    2.7%$72.8MHistory

Share of portfolio

Top 5 holdings and the other 143 positions, by share of portfolio value

  1. VPG5.7%
  2. VIRT4.8%
  3. TTMI3.6%
  4. MOD3.1%
  5. QLYS2.7%
  6. Other 143 positions80.1%

Biggest buys

New and added positions, by estimated amount bought

  1. VIRTVirtu Financial, Inc.
    +$55.4MAddedHistory
  2. FOURShift4 Payments, Inc.
    +$43.8MAddedHistory
  3. PENGPenguin Solutions, Inc.
    +$41.5MNewHistory
  4. QLYSQualys, Inc.
    +$40.0MAddedHistory
  5. ENVAEnova International, Inc.
    +$28.4MAddedHistory

Largest weight increases

New and added positions, by percentage points of the portfolio gained

  1. VIRTVirtu Financial, Inc.
    +1.94 pp2.8% → 4.8%History
  2. QLYSQualys, Inc.
    +1.61 pp1.1% → 2.7%History
  3. PENGPenguin Solutions, Inc.
    +1.55 pp0.0% → 1.6%History
  4. FOURShift4 Payments, Inc.
    +1.53 pp0.5% → 2.0%History
  5. ENVAEnova International, Inc.
    +1.21 pp0.6% → 1.8%History

Biggest sells

Reduced and sold-out positions, by estimated amount sold

  1. TTMITTM Technologies Inc
    −$41.1MReducedHistory
  2. PBFPBF Energy Inc.
    −$38.1MSold outHistory
  3. CRGYCrescent Energy Co
    −$35.1MSold outHistory
  4. FLEXFlex Ltd.
    −$34.7MReducedHistory
  5. BIDUBaidu, Inc.
    −$30.9MReducedHistory

Largest weight decreases

Reduced and sold-out positions, by percentage points of the portfolio lost

  1. PBFPBF Energy Inc.
    −2.03 pp2.0% → 0.0%History
  2. CRGYCrescent Energy Co
    −1.87 pp1.9% → 0.0%History
  3. BIDUBaidu, Inc.
    −1.76 pp2.2% → 0.4%History
  4. MODModine Manufacturing Co
    −1.62 pp4.8% → 3.1%History
  5. PARRPar Pacific Holdings, Inc.
    −1.60 pp2.3% → 0.7%History

Metrics

13F metrics for Q2 2026, computed only from the numbers in the filings. Definitions below.

Portfolio value
$2.67B
+$792.0M (+42.1%) vs. prior quarter
Positions
148
+4 vs. prior quarter
Top 10 concentration
29.0%
Top 10 as share of value
Turnover
34.2%
Q2 2026, one quarter
Average holding period
6.5 quarters
Weighted by value

How these are calculated

  • Portfolio value: the market value of all long positions in the 13F, as reported at quarter end, excluding options.
  • Top 10 concentration: the combined value of the 10 largest positions as a share of portfolio value.
  • Turnover: the smaller of this quarter's estimated purchases and estimated sales, divided by the average of this and last quarter's portfolio value. Estimates multiply the change in shares by the quarter-end price implied by the filing (market value divided by shares); new positions use this quarter's value and sold-out positions last quarter's. Only positions reported in shares count, and it is not calculated when the previous quarter was not filed.
  • Average holding period: how many consecutive quarters each current position has been held (including this one; a quarter without the position or without a filing starts the count over), weighted by this quarter's value. Counting starts with the first 13F in Livermore (Q1 2021), so positions held before then are understated.

13F filings by quarter

22 quarters, going back to Q1 2021. Bars show each quarter's 13F portfolio value; quarters without a filing are left blank.

Peak $2.67B (Q2 2026)

Q1 2021: $1.27BQ2 2021: $1.39BQ3 2021: $1.37BQ4 2021: $1.49BQ1 2022: $1.25BQ2 2022: $993.2MQ3 2022: $946.2MQ4 2022: $1.01BQ1 2023: $1.05BQ2 2023: $1.13BQ3 2023: $1.07BQ4 2023: $1.14BQ1 2024: $1.31BQ2 2024: $1.21BQ3 2024: $1.38BQ4 2024: $1.49BQ1 2025: $1.32BQ2 2025: $1.59BQ3 2025: $1.85BQ4 2025: $1.87BQ1 2026: $1.88BQ2 2026: $2.67B
Q1 2021Q2 2026
13F filings of Portolan Capital Management, LLC by quarter
QuarterFiledPositionsValueTop 3 holdingsChangesFiling
Q2 2026Aug 14, 2026148$2.67BVPGVIRTTTMIvs. Q1 2026SEC
Q1 2026May 15, 2026144$1.88BMODTTMICLSvs. Q4 2025SEC
Q4 2025Feb 17, 2026155$1.87BTTMIMODCSTLvs. Q3 2025SEC
Q3 2025Nov 13, 2025119$1.85BMODTTMIELFvs. Q2 2025SEC
Q2 2025Aug 13, 2025118$1.59BCLSKTOSELFvs. Q1 2025SEC
Q1 2025May 15, 2025109$1.32BLNTHSLMKTOSvs. Q4 2024SEC
Q4 2024Feb 13, 2025131$1.49BLNTHCLSSMTCvs. Q3 2024SEC
Q3 2024Nov 14, 2024129$1.38BLNTHZETAKTOSvs. Q2 2024SEC
Q2 2024Aug 14, 2024117$1.21BLNTHCLSSMCIvs. Q1 2024SEC
Q1 2024May 15, 2024116$1.31BSMCICLSLNTHvs. Q4 2023SEC
Q4 2023Feb 14, 2024127$1.14BSMCIELFCLSvs. Q3 2023SEC
Q3 2023Nov 14, 2023123$1.07BSMCIQTRXELFvs. Q2 2023SEC
Q2 2023Aug 14, 2023120$1.13BSMCIKRUSELFvs. Q1 2023SEC
Q1 2023May 15, 2023139$1.05BSMCIELFKRUSvs. Q4 2022SEC
Q4 2022Feb 13, 2023131$1.01BCROXELFBIOvs. Q3 2022SEC
Q3 2022Nov 14, 2022128$946.2MTAELFLRNvs. Q2 2022SEC
Q2 2022Aug 15, 2022123$993.2MELFDOMOAVIDvs. Q1 2022SEC
Q1 2022May 16, 2022136$1.25BDOMOBANDINVEvs. Q4 2021SEC
Q4 2021Feb 14, 2022131$1.49BINVEBXCCUBIvs. Q3 2021SEC
Q3 2021Nov 15, 2021134$1.37BCROXTADOMOvs. Q2 2021SEC
Q2 2021Aug 16, 2021131$1.39BGPREMGIDOMOvs. Q1 2021SEC
Q1 2021May 17, 2021151$1.27BBWCAI International, Inc.STKL–SEC

13D and 13G filings

Companies where Portolan Capital Management, LLC reports owning 5% or more on Schedule 13D or 13G, and its latest filings.

Current stakes of 5% or more

9 companies, largest stake first.

Companies where Portolan Capital Management, LLC owns 5% or more
CompanyLatest formStakeChangeFirst filedLatest filingFiling
VPGVishay Precision Group, Inc.13G/A8.31%1.02M shares+1.59 ppfrom 6.72%Feb 6, 20254 filingsMay 15, 2026SEC
FORRForrester Research, Inc.13G/A7.94%1.54M shares+1.82 ppfrom 6.12%Feb 19, 20262 filingsMay 15, 2026SEC
GOOSCanada Goose Holdings Inc.13G6.31%2.91M sharesNewJan 16, 20261 filingJan 16, 2026SEC
LPROOpen Lending Corp13G5.93%7.01M sharesNewFeb 26, 20261 filingFeb 26, 2026SEC
MECMayville Engineering Company, Inc.13G5.92%1.47M sharesNewMay 28, 20261 filingMay 28, 2026SEC
PBPBPotbelly Corp13G5.53%1.67M sharesNewJun 27, 20251 filingJun 27, 2025SEC
TGENTecogen Inc.13G5.19%1.55M sharesNewJun 10, 20261 filingJun 10, 2026SEC
Real Brokerage IncCommon Shares, no par value13G/A5.07%11.0M shares−1.73 ppfrom 6.80%Jan 8, 20263 filingsAug 14, 2026SEC
SILCSilicom Ltd.13G5.06%288.8K sharesNewSep 30, 20261 filingSep 30, 2026SEC

Latest filings

101 filings on file made by Portolan Capital Management, LLC or listing it as a reporting person; the latest 20 are shown.

Schedule 13D and 13G filings by Portolan Capital Management, LLC
CompanyFiled (ET)FormStakeChangeEvent dateFiling
SILCSilicom Ltd.Sep 30, 20265:05 PM ET13G5.06%288.8K sharesNewSep 23, 2026SEC
Real Brokerage IncCommon Shares, no par valueAug 14, 20263:10 PM ET13G/A5.07%11.0M shares−1.73 ppfrom 6.80%Jun 30, 2026SEC
QTRXQuanterix CorpAug 14, 20263:10 PM ET13G/A4.02%1.90M shares−2.23 ppfrom 6.25%Below 5%Jun 30, 2026SEC
TGENTecogen Inc.Jun 10, 20265:59 PM ET13G5.19%1.55M sharesNewJun 3, 2026SEC
MECMayville Engineering Company, Inc.May 28, 20266:50 PM ET13G5.92%1.47M sharesNewMay 20, 2026SEC
CSTLCastle Biosciences IncMay 15, 20264:10 PM ET13G/A4.45%1.35M shares−1.20 ppfrom 5.65%Below 5%Mar 31, 2026SEC
VPGVishay Precision Group, Inc.May 15, 20264:09 PM ET13G/A8.31%1.02M shares+1.59 ppfrom 6.72%Mar 31, 2026SEC
Real Brokerage IncCommon Shares, no par valueMay 15, 20264:07 PM ET13G/A6.80%14.5M shares+1.44 ppfrom 5.36%Mar 31, 2026SEC
QTRXQuanterix CorpMay 15, 20264:06 PM ET13G/A6.25%2.95M shares−3.11 ppfrom 9.36%Mar 31, 2026SEC
FORRForrester Research, Inc.May 15, 20264:05 PM ET13G/A7.94%1.54M shares+1.82 ppfrom 6.12%Mar 31, 2026SEC
DOMOHuckleberry.ai, Inc.May 15, 20264:03 PM ET13G/A0.47%197.1K shares−5.13 ppfrom 5.60%Below 5%Mar 31, 2026SEC
LPROOpen Lending CorpFeb 26, 20264:01 PM ET13G5.93%7.01M sharesNewFeb 19, 2026SEC
FORRForrester Research, Inc.Feb 19, 20265:43 PM ET13G6.12%1.16M sharesNewFeb 11, 2026SEC
HNSTHonest Company, Inc.Feb 17, 20263:51 PM ET13G/A4.30%4.80M shares−1.01 ppfrom 5.31%Below 5%Dec 31, 2025SEC
MAMAMama's Creations, Inc.Feb 17, 20263:48 PM ET13G/A3.06%1.25M shares−2.18 ppfrom 5.24%Below 5%Dec 31, 2025SEC
DOMOHuckleberry.ai, Inc.Feb 17, 20263:47 PM ET13G/A5.60%2.16M shares−1.47 ppfrom 7.07%Dec 31, 2025SEC
GOOSCanada Goose Holdings Inc.Jan 16, 20264:04 PM ET13G6.31%2.91M sharesNewJan 9, 2026SEC
Real Brokerage IncCommon Shares, no par valueJan 8, 20266:51 PM ET13G5.36%11.3M sharesNewDec 31, 2025SEC
DOMOHuckleberry.ai, Inc.Nov 13, 20254:04 PM ET13G/A7.07%2.68M shares+1.02 ppfrom 6.05%Sep 30, 2025SEC
VPGVishay Precision Group, Inc.Nov 13, 20254:03 PM ET13G/A6.72%823.3K shares−1.38 ppfrom 8.10%Sep 30, 2025SEC