HolderBook

Atika Capital Management LLC

Reported holdings as of Q2 2026, from 31 quarterly filings.

This filer last reported in Q2 2026; the most recent quarter on file across all filers is Q3 2026. Firms that restructure stop filing under one CIK and start under another, so a successor entity may hold these positions now under a similar name.

CIK
1599731
Reported value
$1.5B
Positions
75
Top 10 weight
53.6%
Filed
2026-08-13
Days after quarter end
44

Holdings

Download these holdings as CSV

SecurityTickerValue SharesWeightWeight change Held Change
VERTIV HOLDINGS COVRT$223.0M666,10014.66%-6.30pp13qHELD
INVESCO QQQ TR CALL+PUTQQQ$122.2Moptions only8.03%-newOPTIONS
SPDR SERIES TRUST PUTXBI$89.0Moptions only5.85%-0.93pp3qOPTIONS
SEAGATE TECHNOLOGY HLDNGS PLSTX$77.1M79,8655.07%+2.43pp4q+49.3%+$25.4M
AMAZON COM INC CALLAMZN$63.4M44,0004.17%+3.02pp14q+0.7%+$432.3K
GE VERNOVA INC PUTGEV$58.7Moptions only3.86%-newOPTIONS
ADVANCED MICRO DEVICES INCAMD$55.5M95,5003.65%-newNEW
ELI LILLY & COLLY$49.3M41,1003.24%-1.51pp13qHELD
ECHOSTAR CORP CALLECHO$40.8M331,4002.68%-2.32pp7q+82.1%+$18.4M
INTEL CORPINTC$36.9M264,0002.42%+1.87pp2qHELD
MICRON TECHNOLOGY INC PUTMU$34.6Moptions only2.28%-newOPTIONS
VANECK ETF TRUST PUTSMH$33.5Moptions only2.20%-1.27pp2qOPTIONS
GUARDANT HEALTH INCGH$27.2M181,0001.78%+0.73pp6q+98.9%+$13.5M
ISHARES TR PUTIGV$24.6Moptions only1.62%-newOPTIONS
CIENA CORPCIEN$23.9M48,7681.57%-0.56pp4q+11.7%+$2.5M
INTUITIVE SURGICAL INCISRG$22.8M57,2161.50%-1.82pp16qHELD
BRITISH AMERN TOB PLC CALLBTI$20.4Moptions only1.34%-newOPTIONS
ISHARES BITCOIN TRUST ETF PUTIBIT$20.0Moptions only1.31%-newOPTIONS
TEVA PHARMACEUTICAL INDS LTD CALLTEVA$18.3M440,0001.20%-0.60pp4q-7.8%-$1.5M
VISHAY PRECISION GROUP INCVPG$17.7M118,0001.16%-newNEW
MARVELL TECHNOLOGY INCMRVL$17.3M58,0001.14%-newNEW
ROCKET LAB CORPRKLB$17.2M169,0001.13%+0.44pp3q+96.5%+$8.4M
WESTERN DIGITAL CORPWDC$16.9M26,4771.11%-0.17pp2q-29.8%-$7.2M
REVOLUTION MEDICINES INCRVMD$16.5M88,0001.08%-newNEW
ASCENDIS PHARMA A/SASND$16.3M61,0001.07%-newNEW
DIANTHUS THERAPEUTICS INCDNTH$16.1M165,0001.06%-0.30pp3q+28.1%+$3.5M
ROUNDHILL ETF TRUST PUT$15.5Moptions only1.02%-newOPTIONS
AXSOME THERAPEUTICS INCAXSM$15.4M63,0001.01%-newNEW
MASTEC INCMTZ$14.8M35,5000.97%-1.36pp5q-38.4%-$9.2M
SHARKNINJA INCSN$13.4M88,0000.88%-newNEW
NETFLIX INCNFLX$12.9M180,0000.84%-3.32pp8qHELD
STUBHUB HLDGS INC CALLSTUB$12.2M50,0000.80%-newNEW
CURTISS WRIGHT CORPCW$12.1M16,0000.80%-0.31pp5q+23.1%+$2.3M
KYMERA THERAPEUTICS INCKYMR$11.9M104,0000.78%-newNEW
ALKERMES PLC CALLALKS$11.3M55,5710.74%-newNEW
SITIME CORPSITM$11.2M15,0000.74%+0.09pp2q+1.3%+$145.4K
TWIST BIOSCIENCE CORPTWST$11.1M108,0000.73%-newNEW
THE REALREAL INCREAL$11.1M940,0000.73%+0.21pp4q+108.4%+$5.8M
COGENT BIOSCIENCES INCCOGT$10.5M272,0000.69%-0.73pp3q-7.2%-$820.4K
BWX TECHNOLOGIES INCBWXT$10.5M54,0000.69%-1.43pp17q-34.6%-$5.6M
BBB FOODS INCTBBB$10.4M250,0000.68%+0.26pp10q+162.6%+$6.4M
AXOGEN INCAXGN$10.2M221,0000.67%-newNEW
NOKIA CORPNOK$10.0M750,0000.65%-newNEW
ORUKA THERAPEUTICS INCORKA$9.5M100,0000.63%-0.79pp2q-56.5%-$12.4M
TTM TECHNOLOGIES INCTTMI$9.4M50,0000.61%-0.52pp3q-46.2%-$8.0M
CHARLES RIV LABS INTL INCCRL$8.6M38,0000.57%-newNEW
ACM RESH INCACMR$8.0M63,0000.53%-newNEW
ROIVANT SCIENCES LTDROIV$7.7M217,0000.50%-newNEW
MERCADOLIBRE INCMELI$7.7M4,5100.50%-0.48pp14qHELD
APPFOLIO INCAPPF$7.6M47,5000.50%-0.44pp13qHELD
PROTAGONIST THERAPEUTICS INCPTGX$7.6M62,1000.50%-0.32pp4qHELD
REDDIT INCRDDT$7.5M43,0000.49%-newNEW
SEMTECH CORPSMTC$7.4M46,0000.49%-newNEW
FIVE BELOW INCFIVE$7.2M40,0000.47%-0.66pp4q+1.3%+$93.5K
FERGUSON ENTERPRISES INCFERG$7.0M29,3000.46%-0.40pp8qHELD
ENPHASE ENERGY INC CALLENPH$5.9Moptions only0.39%-newOPTIONS
DEFINIUM THERAPEUTICS INCDFTX$5.7M122,0000.38%-newNEW
IMMUNOME INCIMNM$5.6M262,9000.37%-0.36pp3qHELD
HUT 8 CORPHUT$5.1M44,5000.34%+0.05pp2q-9.7%-$554.1K
WARBY PARKER INCWRBY$4.6M150,0000.30%-0.06pp3q+11.1%+$455.1K
JATT II ACQUISITION CORP$4.5M400,0000.30%-newNEW
PRAXIS PRECISION MEDICINES IPRAX$4.3M12,9000.28%-newNEW
NLIGHT INCLASR$3.8M55,0000.25%-0.22pp2q-16.7%-$765.8K
ABIVAX SAABVX$3.6M27,0000.24%-0.17pp4q-6.2%-$239.9K
COREWEAVE INC CALLCRWV$3.5Moptions only0.23%-newOPTIONS
CROWDSTRIKE HLDGS INCCRWD$2.9M3,8000.19%-newNEW
TARSUS PHARMACEUTICALS INCTARS$2.5M40,0000.17%-newNEW
KRYSTAL BIOTECH INCKRYS$2.2M6,0000.15%-0.20pp2q-43.5%-$1.7M
VERICEL CORPVCEL$1.5M34,0000.10%-newNEW
VERADERMICS INCMANE$1.5M12,0000.10%-newNEW
KINIKSA PHARMACEUTICALS INTLKNSA$1.5M23,0000.10%-newNEW
CLEVELAND-CLIFFS INC NEW CALLCLF$1.4Moptions only0.09%-newOPTIONS
SWEETGREEN INCSG$1.1M120,0000.07%-newNEW
KEEL INFRASTRUCTURE CORP CALLKEEL$861.0Koptions only0.06%-newOPTIONS
SANDISK CORPSNDK$688.9K3030.05%-newNEW

By sector

Industry comes from the SIC code on each company's own SEC filings, which is self-reported and sometimes out of date. Derivative exposure is counted with the shares. Securities the SEC assigns no industry - funds, trusts, foreign issues - are shown as not classified rather than dropped.

Semiconductors & Electronics 34.7%Biotech & Pharma 15.7%Funds & ETFs 8.0%Computer Hardware 6.2%Retail & Consumer 6.1%Telecom & Media 4.3%Medical Devices 2.5%Industrials 2.0%Healthcare Services 1.8%Other sectors 7.6%Not classified 11.0%
 
SectorValueShare
Semiconductors & Electronics$528.7M34.7%
Biotech & Pharma$238.6M15.7%
Funds & ETFs$122.2M8.0%
Computer Hardware$94.7M6.2%
Retail & Consumer$93.1M6.1%
Telecom & Media$65.9M4.3%
Medical Devices$37.5M2.5%
Industrials$30.6M2.0%
Healthcare Services$27.2M1.8%
Other sectors$115.8M7.6%
Not classified$167.2M11.0%

What the disclosed book did

This is not the fund's return. A 13F shows long US equity positions only, so shorts, bonds, foreign listings, private holdings and cash are all invisible here. What this measures is the quarter's change in value of the positions this manager disclosed, had they been left untouched - the return a reader following the filing would have earned.

QuarterBookMarket DifferencePriced
Q2 2026+26.4%+14.8%+11.6%90%
Q1 2026+7.0%-4.6%+11.6%92%
Q4 2025+3.4%+2.4%+1.1%95%
Q3 2025+6.9%+7.8%-0.9%98%
Q2 2025+24.3%+10.5%+13.9%98%
Q1 2025-9.5%-4.6%-4.9%100%
Q4 2024-0.3%+2.1%-2.4%99%
Q3 2024+6.8%+5.4%+1.4%97%

Market is SPY over the same two quarter ends, priced the same way as everything else here - the median across every filer reporting it. It is a large-cap US proxy, so a manager holding small caps or biotech will beat or trail it for reasons that are not skill. Prices are quarter-end to quarter-end and say nothing about the path in between, or about trades opened and closed inside a quarter.

Quarter by quarter

QuarterValuePositions NewAddedTrimmed ExitedTop 10 Days to file
Q2 2026$1.5B753913112053.6%44
Q1 2026$796.4M561611233456.8%44
Q4 2025$949.8M743315224049.1%44
Q3 2025$1.2B813120181142.4%44
Q2 2025$1,000.0M611825151650.2%44
Q1 2025$711.1M591521173946.7%44
Q4 2024$941.4M83319323038.2%44
Q3 2024$975.4M822624203340.0%44
Q2 2024$1.0B893217323040.3%44
Q1 2024$1.0B873822212433.5%44
Q4 2023$746.8M732315332333.0%44
Q3 2023$761.9M732515253030.5%44
Q2 2023$999.0M782822212539.4%42
Q1 2023$677.1M753011291840.2%42
Q4 2022$695.5M63217324042.7%44
Q3 2022$1.2B823524162633.1%45
Q2 2022$889.6M732815232139.2%43
Q1 2022$1.2B662115234038.5%43
Q4 2021$1.4B852622295028.6%42
Q3 2021$1.7B1094433212632.1%43
Q2 2021$1.3B913018272629.6%43
Q1 2021$1.2B872011503428.8%44
Q4 2020$1.3B1014226284025.0%47
Q3 2020$1.2B993025271835.6%44
Q2 2020$773.8M873321292531.3%44
Q1 2020$521.8M793222222740.4%44
Q4 2019$517.9M742221241530.3%45
Q3 2019$475.0M671225242032.0%45
Q2 2019$509.1M752517202130.6%43
Q1 2019$492.2M712320141434.7%43
Q4 2018$339.7M62000036.9%45

Rows marked UNVERIFIED ID, PLACEHOLDER ID, TICKER AS ID or NON-CUSIP ID carry an identifier that is not a valid CUSIP. They are shown because the filer reported that money, but treat the security named with caution - hover the chip for what is wrong with it, and see the methodology.

Held counts consecutive filings in which this manager reported the position, and can reach further back than the quarters listed above: the tabs begin at Q4 2018 because earlier coverage is too sparse to describe a market, but tenure is counted over every filing we hold, some reaching to 2007. A position sold and later rebought starts again from one.

Weight change is the shift in this position's share of the whole book, in percentage points. It is the more useful column: when money flows into or out of a broad fund, almost every holding is bought or sold at once, so added and trimmed largely track flows. A weight that rose while the book shrank is a decision. Both compare with the previous quarter this filer reported, not the previous calendar quarter.