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Livermore
Livermore
ZHEN

Atika Capital Management LLC

SEC CIK
0001599731
Latest filing
Aug 13, 2026

The latest 13F from Atika Capital Management LLC covers Q2 2026 (filed Aug 13, 2026): 62 long positions worth $1.01B. The top 10 holdings make up 56.3% of the portfolio, and the largest is Vertiv Holdings Co (VRT) at 22.1%. 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
28
Est. +$284.8M
Added
14
Est. +$95.0M
Reduced
11
Est. −$47.7M
Sold out
18
Est. −$116.4M

Top 5 holdings

Share of this quarter's portfolio value

  1. VRTVertiv Holdings Co
    22.1%$223.0MHistory
  2. STXSeagate Technology Holdings plc
    7.6%$77.1MHistory
  3. AMDAdvanced Micro Devices Inc
    5.5%$55.5MHistory
  4. LLYEli Lilly & Co
    4.9%$49.3MHistory
  5. INTCIntel Corp
    3.7%$36.9MHistory

Share of portfolio

Top 5 holdings and the other 57 positions, by share of portfolio value

  1. VRT22.1%
  2. STX7.6%
  3. AMD5.5%
  4. LLY4.9%
  5. INTC3.7%
  6. Other 57 positions56.2%

Biggest buys

New and added positions, by estimated amount bought

  1. AMDAdvanced Micro Devices Inc
    +$55.5MNewHistory
  2. INTCIntel Corp
    +$36.9MNewHistory
  3. STXSeagate Technology Holdings plc
    +$25.4MAddedHistory
  4. VPGVishay Precision Group, Inc.
    +$17.7MNewHistory
  5. MRVLMarvell Technology, Inc.
    +$17.3MNewHistory

Largest weight increases

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

  1. AMDAdvanced Micro Devices Inc
    +5.50 pp0.0% → 5.5%History
  2. STXSeagate Technology Holdings plc
    +4.34 pp3.3% → 7.6%History
  3. INTCIntel Corp
    +3.66 pp0.0% → 3.7%History
  4. VPGVishay Precision Group, Inc.
    +1.76 pp0.0% → 1.8%History
  5. MRVLMarvell Technology, Inc.
    +1.71 pp0.0% → 1.7%History

Biggest sells

Reduced and sold-out positions, by estimated amount sold

  1. TERNTerns Pharmaceuticals, Inc.
    −$15.8MSold outHistory
  2. NETCloudflare, Inc.
    −$13.4MSold outHistory
  3. GOOGAlphabet Inc.
    −$12.4MSold outHistory
  4. ORKAOruka Therapeutics, Inc.
    −$12.4MReducedHistory
  5. MTZMastec Inc
    −$9.21MReducedHistory

Largest weight decreases

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

  1. TERNTerns Pharmaceuticals, Inc.
    −2.50 pp2.5% → 0.0%History
  2. NETCloudflare, Inc.
    −2.12 pp2.1% → 0.0%History
  3. GOOGAlphabet Inc.
    −1.96 pp2.0% → 0.0%History
  4. BWXTBWX Technologies, Inc.
    −1.62 pp2.7% → 1.0%History
  5. MTZMastec Inc
    −1.46 pp2.9% → 1.5%History

Metrics

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

Portfolio value
$1.01B
+$374.1M (+59.0%) vs. prior quarter
Positions
62
+10 vs. prior quarter
Top 10 concentration
56.3%
Top 10 as share of value
Turnover
20.0%
Q2 2026, one quarter
Average holding period
6.4 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 $1.40B (Q3 2021)

Q1 2021: $959.2MQ2 2021: $1.21BQ3 2021: $1.40BQ4 2021: $1.22BQ1 2022: $1.05BQ2 2022: $765.7MQ3 2022: $883.7MQ4 2022: $655.0MQ1 2023: $641.6MQ2 2023: $795.8MQ3 2023: $702.0MQ4 2023: $703.4MQ1 2024: $891.5MQ2 2024: $862.5MQ3 2024: $935.1MQ4 2024: $772.3MQ1 2025: $651.3MQ2 2025: $957.3MQ3 2025: $1.17BQ4 2025: $718.1MQ1 2026: $633.6MQ2 2026: $1.01B
Q1 2021Q2 2026
13F filings of Atika Capital Management LLC by quarter
QuarterFiledPositionsValueTop 3 holdingsChangesFiling
Q2 2026Aug 13, 202662$1.01BVRTSTXAMDvs. Q1 2026SEC
Q1 2026May 14, 202652$633.6MVRTLLYISRGvs. Q4 2025SEC
Q4 2025Feb 13, 202664$718.1MVRTLLYISRGvs. Q3 2025SEC
Q3 2025Nov 13, 202576$1.17BVRTAMZNMSFTvs. Q2 2025SEC
Q2 2025Aug 13, 202557$957.3MAMZNVRTMSFTvs. Q1 2025SEC
Q1 2025May 14, 202553$651.3MAMZNMSFTVRTvs. Q4 2024SEC
Q4 2024Feb 13, 202573$772.3MMSFTVRTAMZNvs. Q3 2024SEC
Q3 2024Nov 13, 202474$935.1MNVDAMSFTMELIvs. Q2 2024SEC
Q2 2024Aug 13, 202475$862.5MNVDAMSFTAMZNvs. Q1 2024SEC
Q1 2024May 14, 202479$891.5MNVDASWAVMSFTvs. Q4 2023SEC
Q4 2023Feb 13, 202469$703.4MAMDMELIMSFTvs. Q3 2023SEC
Q3 2023Nov 13, 202369$702.0MINSPMSFTSWAVvs. Q2 2023SEC
Q2 2023Aug 11, 202370$795.8MINSPNVDASWAVvs. Q1 2023SEC
Q1 2023May 12, 202369$641.6MPIINSPFWONKvs. Q4 2022SEC
Q4 2022Feb 13, 202357$655.0MCALXPICLFDvs. Q3 2022SEC
Q3 2022Nov 14, 202261$883.7MCALXFWONKCLFDvs. Q2 2022SEC
Q2 2022Aug 12, 202255$765.7MSWAVSGENFWONKvs. Q1 2022SEC
Q1 2022May 13, 202258$1.05BPANWSWAVAMZNvs. Q4 2021SEC
Q4 2021Feb 11, 202274$1.22BMSFTGOOGCALXvs. Q3 2021SEC
Q3 2021Nov 12, 202197$1.40BUPSTGOOGAMZNvs. Q2 2021SEC
Q2 2021Aug 12, 202183$1.21BZLABAVIDROKUvs. Q1 2021SEC
Q1 2021May 14, 202178$959.2MZLABZINSP–SEC

13D and 13G filings

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

Current stakes of 5% or more

1 company, largest stake first.

Companies where Atika Capital Management LLC owns 5% or more
CompanyLatest formStakeChangeFirst filedLatest filingFiling
JATTJATT II Acquisition Corp.13G5.10%400.0K sharesNewAug 14, 20261 filingAug 14, 2026SEC

Latest filings

1 filing on file made by Atika Capital Management LLC or listing it as a reporting person, newest first.

Schedule 13D and 13G filings by Atika Capital Management LLC
CompanyFiled (ET)FormStakeChangeEvent dateFiling
JATTJATT II Acquisition Corp.Aug 14, 20267:32 AM ET13G5.10%400.0K sharesNewJun 30, 2026SEC