Skip to main content
Livermore
Livermore
ZHEN

Gagnon Securities LLC

SEC CIK
0001125725
Latest filing
Aug 4, 2026

The latest 13F from Gagnon Securities LLC covers Q2 2026 (filed Aug 4, 2026): 83 long positions worth $518.8M. The top 10 holdings make up 47.7% of the portfolio, and the largest is CareDx, Inc. (CDNA) at 9.7%. 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
4
Est. +$12.7M
Added
25
Est. +$45.2M
Reduced
46
Est. −$24.1M
Sold out
6
Est. −$31.1M

Top 5 holdings

Share of this quarter's portfolio value

  1. CDNACareDx, Inc.
    9.7%$50.5MHistory
  2. WGSGeneDx Holdings Corp.
    6.9%$36.0MHistory
  3. ENSGEnsign Group, Inc
    5.4%$27.9MHistory
  4. AMRCAmeresco, Inc.
    4.4%$22.8MHistory
  5. GNRCGenerac Holdings Inc.
    4.1%$21.4MHistory

Biggest buys

New and added positions, by estimated amount bought

  1. WGSGeneDx Holdings Corp.
    +$15.2MAddedHistory
  2. 0000000000
    +$11.7MNew
  3. QDELQuidelOrtho Corp
    +$11.0MAddedHistory
  4. HNGEHinge Health, Inc.
    +$4.87MAddedHistory
  5. VERXVertex, Inc.
    +$3.36MAddedHistory

Largest weight increases

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

  1. CDNACareDx, Inc.
    +2.67 pp7.1% → 9.7%History
  2. WGSGeneDx Holdings Corp.
    +2.45 pp4.5% → 6.9%History
  3. 0000000000
    +2.25 pp0.0% → 2.3%
  4. QDELQuidelOrtho Corp
    +1.95 pp1.5% → 3.5%History
  5. HNGEHinge Health, Inc.
    +1.82 pp1.1% → 2.9%History

Biggest sells

Reduced and sold-out positions, by estimated amount sold

  1. NVGSNavigator Holdings Ltd.
    −$17.1MSold outHistory
  2. iShares Tr46436E718
    −$9.33MSold out
  3. TMCITreace Medical Concepts, Inc.
    −$8.65MReducedHistory
  4. AOSLAlpha & Omega Semiconductor Ltd
    −$3.72MSold outHistory
  5. PTENPatterson Uti Energy Inc
    −$2.73MReducedHistory

Largest weight decreases

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

  1. NVGSNavigator Holdings Ltd.
    −3.96 pp4.0% → 0.0%History
  2. ENSGEnsign Group, Inc
    −2.98 pp8.4% → 5.4%History
  3. iShares Tr46436E718
    −2.15 pp2.2% → 0.0%
  4. ISRGIntuitive Surgical Inc
    −1.13 pp3.4% → 2.2%History
  5. EPDEnterprise Products Partners L.P.
    −0.87 pp4.5% → 3.6%History

Metrics

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

Portfolio value
$518.8M
+$85.6M (+19.8%) vs. prior quarter
Positions
83
−2 vs. prior quarter
Top 10 concentration
47.7%
Top 10 as share of value
Turnover
11.6%
Q2 2026, one quarter
Average holding period
17.4 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 $704.3M (Q2 2021)

Q1 2021: $656.7MQ2 2021: $704.3MQ3 2021: $673.1MQ4 2021: $666.7MQ1 2022: $613.2MQ2 2022: $477.1MQ3 2022: $454.8MQ4 2022: $451.6MQ1 2023: $475.8MQ2 2023: $480.9MQ3 2023: $399.1MQ4 2023: $416.6MQ1 2024: $422.5MQ2 2024: $444.0MQ3 2024: $504.4MQ4 2024: $496.3MQ1 2025: $454.5MQ2 2025: $492.4MQ3 2025: $498.5MQ4 2025: $491.1MQ1 2026: $433.2MQ2 2026: $518.8M
Q1 2021Q2 2026
13F filings of Gagnon Securities LLC by quarter
QuarterFiledPositionsValueTop 3 holdingsChangesFiling
Q2 2026Aug 4, 202683$518.8MCDNAWGSENSGvs. Q1 2026SEC
Q1 2026Apr 22, 202685$433.2MENSGCDNAAMRCvs. Q4 2025SEC
Q4 2025Feb 13, 202686$491.1MCDNAWGSALvs. Q3 2025SEC
Q3 2025Nov 3, 202586$498.5MALENSGWGSvs. Q2 2025SEC
Q2 2025Jul 23, 202587$492.4MALENSGCDNAvs. Q1 2025SEC
Q1 2025May 9, 202598$454.5MALENSGISRGvs. Q4 2024SEC
Q4 2024Jan 24, 202591$496.3MALISRGCDNAvs. Q3 2024SEC
Q3 2024Nov 12, 2024102$504.4MCDNAENSGALvs. Q2 2024SEC
Q2 2024Aug 14, 202497$444.0MALCDNAENSGvs. Q1 2024SEC
Q1 2024May 13, 202498$422.5MALENSGCDNAvs. Q4 2023SEC
Q4 2023Feb 14, 2024102$416.6MALENSGCDNAvs. Q3 2023SEC
Q3 2023Nov 14, 202397$399.1MALENSGISRGvs. Q2 2023SEC
Q2 2023Aug 8, 202397$480.9MALENSGISRGvs. Q1 2023SEC
Q1 2023Apr 10, 2023112$475.8MALENSGNVGSvs. Q4 2022SEC
Q4 2022Feb 7, 2023105$451.6MALENSGPCRXvs. Q3 2022SEC
Q3 2022Nov 14, 2022101$454.8MPCRXALENSGvs. Q2 2022SEC
Q2 2022Aug 1, 2022101$477.1MPCRXALENSGvs. Q1 2022SEC
Q1 2022May 9, 2022103$613.2MPCRXALCDNAvs. Q4 2021SEC
Q4 2021Feb 8, 2022104$666.7MALAOSLCDNAvs. Q3 2021SEC
Q3 2021Nov 12, 2021112$673.1MCDNAALPCRXvs. Q2 2021SEC
Q2 2021Jul 28, 2021111$704.3MCDNAALENSGvs. Q1 2021SEC
Q1 2021May 14, 2021108$656.7MCDNAALENSG–SEC

13D and 13G filings

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

Current stakes of 5% or more

7 companies, largest stake first.

Companies where Gagnon Securities LLC owns 5% or more
CompanyLatest formStakeChangeFirst filedLatest filingFiling
PROFProfound Medical Corp.13G/A11.20%3.35M shares–Feb 9, 202110 filingsJan 23, 2025SEC
TMCITreace Medical Concepts, Inc.13G/A9.60%6.14M shares+3.30 ppfrom 6.30%May 15, 20252 filingsFeb 12, 2026SEC
PSIXPower Solutions International, Inc.13G/A7.30%1.68M shares0.00 ppfrom 7.30%Jan 23, 20252 filingsJan 23, 2025SEC
CNFCNFinance Holdings Ltd.13G/A6.80%93.3M shares0.00 ppfrom 6.80%Nov 14, 20252 filingsFeb 12, 2026SEC
OSUROrasure Technologies Inc13G5.80%8.87M sharesNewAug 12, 20261 filingAug 12, 2026SEC
OSUROrasure Technologies Inc13G5.40%3.75M shares+0.50 ppfrom 4.90%Nov 17, 20253 filingsApr 8, 2026SEC
AMRCAmeresco, Inc.13G5.00%1.76M shares+0.10 ppfrom 4.90%Oct 24, 20252 filingsAug 27, 2026SEC

Latest filings

36 filings on file made by Gagnon Securities LLC or listing it as a reporting person; the latest 20 are shown.

Schedule 13D and 13G filings by Gagnon Securities LLC
CompanyFiled (ET)FilerFormStakeChangeEvent dateFiling
AMRCAmeresco, Inc.Aug 27, 20263:34 PM ETGagnon Securities LLCand 2 others13G5.00%1.76M shares+0.10 ppfrom 4.90%Aug 20, 2026SEC
OSUROrasure Technologies IncAug 12, 20266:06 PM ETGagnon Securities LLCand 2 others13G5.80%8.87M sharesNewAug 5, 2026SEC
CDNACareDx, Inc.Aug 7, 20265:49 PM ETGagnon Securities LLCand 2 others13G/A4.40%2.29M shares−1.50 ppfrom 5.90%Below 5%Jul 31, 2026SEC
OSUROrasure Technologies IncApr 8, 20266:34 PM ETGagnon Securities LLCand 2 others13G5.40%3.75M shares+0.50 ppfrom 4.90%Jan 8, 2026SEC
TMCITreace Medical Concepts, Inc.Feb 12, 20265:57 PM ETGagnon Securities LLCand 2 others13G/A9.60%6.14M shares+3.30 ppfrom 6.30%Dec 31, 2025SEC
OSUROrasure Technologies IncFeb 12, 20265:56 PM ETGagnon Securities LLCand 2 others13G/A4.90%3.57M shares−0.10 ppfrom 5.00%Below 5%Dec 31, 2025SEC
CNFCNFinance Holdings Ltd.Feb 12, 20265:55 PM ETGagnon Securities LLCand 2 others13G/A6.80%93.3M shares0.00 ppfrom 6.80%Dec 31, 2025SEC
CDNACareDx, Inc.Feb 12, 20265:54 PM ETGagnon Securities LLCand 2 others13G/A5.90%3.05M shares+0.70 ppfrom 5.20%Dec 31, 2025SEC
OSUROrasure Technologies IncNov 17, 20254:06 PM ETGagnon Securities LLCand 2 others13G5.00%3.59M sharesNewNov 11, 2025SEC
CNFCNFinance Holdings Ltd.Nov 14, 20253:42 PM ETGagnon Securities LLCand 2 others13G/A6.80%93.3M shares–Sep 30, 2025SEC
AMRCAmeresco, Inc.Oct 24, 20254:02 PM ETGagnon Securities LLCand 2 others13G/A4.90%1.72M shares–Below 5%Sep 30, 2025SEC
CDNACareDx, Inc.Jul 24, 20254:28 PM ETGagnon Securities LLCand 2 others13G5.20%2.89M shares–Jul 17, 2025SEC
TMCITreace Medical Concepts, Inc.May 15, 20254:30 PM ETGagnon Securities LLCand 2 others13G6.30%3.98M sharesNewMay 9, 2025SEC
CNFCNFinance Holdings Ltd.Mar 12, 20259:23 PM ETGagnon Neiland 2 others13G5.10%70.4M sharesNewFeb 27, 2025SEC
AMRCAmeresco, Inc.Mar 10, 20256:26 PM ETGagnon Neiland 2 others13G5.00%1.74M shares–Mar 3, 2025SEC
PSIXPower Solutions International, Inc.Feb 14, 20251:17 PM ETGagnon Neiland 2 others13G/A5.00%1.14M shares–Feb 5, 2025SEC
PROFProfound Medical Corp.Jan 23, 20256:38 PM ETGagnon Securities LLCand 2 others13G/A11.20%3.35M shares–Dec 31, 2024SEC
PSIXPower Solutions International, Inc.Jan 23, 20256:02 PM ETGagnon Securities LLCand 2 others13G/A7.30%1.68M shares0.00 ppfrom 7.30%Dec 31, 2024SEC
PSIXPower Solutions International, Inc.Jan 23, 20256:02 PM ETGagnon Securities LLCand 2 others13G/A7.30%1.68M shares–Dec 31, 2024SEC
PROFProfound Medical Corp.Nov 14, 2024Gagnon Securities LLC13G/AOld format–––SEC