ILLUMINA INC (ILMN) Stock Institutional Trading Activity


ILLUMINA INC (ILMN) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Renaissance Technologies LLC, Triple Frond Partners, ARK Invest, Sequoia Financial Advisors, and AKO Capital. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q2 2019Viking Global InvestorsBuy188,7631,371,087$504,766
Q1 2019ARK InvestBuy150,313466,953$145,078
Q1 2019Renaissance Technologies LLCBuy168,600193,118$60,000
Q1 2019Viking Global InvestorsBuy38,3701,182,324$367,336
Q4 2018ARK InvestBuy45,819316,640$94,970
Q4 2018Renaissance Technologies LLCSell-14,70024,518$7,354
Q4 2018Viking Global InvestorsBuy758,7641,143,954$343,106
Q3 2018ARK InvestSell-62,044270,821$99,408
Q3 2018Renaissance Technologies LLCBuy21,00039,218$14,395
Q3 2018Viking Global InvestorsSell-115,573385,190$141,388
Q2 2018ARK InvestBuy81,265332,865$92,966
Q2 2018Viking Global InvestorsBuy150,798500,763$139,858
Q1 2018Renaissance Technologies LLCSell-25,60018,218$4,307
Q1 2018ARK InvestBuy85,491251,600$59,483
Q4 2017Renaissance Technologies LLCSell-89,40043,818$9,574
Q4 2017ARK InvestBuy39,810166,109$36,293
Q3 2017ARK InvestBuy22,490126,299$25,159
Q3 2017Renaissance Technologies LLCSell-137,700133,218$26,537
Q2 2017ARK InvestSell-16,076103,809$18,013
Q2 2017Renaissance Technologies LLCBuy147,700270,918$47,010
Q1 2017ARK InvestSell-36,228119,885$20,457
Q4 2016ARK InvestBuy156,113156,113$19,989
Q4 2016Viking Global InvestorsSell-1,439,521349,965$44,810
Q1 2016Lone Pine CapitalSell-1,934,6771,675,158$271,560
Q4 2015Lone Pine CapitalBuy1003,609,835$692,890
Q3 2015Renaissance Technologies LLCBuy28,100123,218$21,664
Q3 2015Viking Global InvestorsSell-3,179,4701,789,486$314,627
Q3 2015Lone Pine CapitalSell-2,068,8023,609,735$634,664
Q2 2015Renaissance Technologies LLCSell-23,20095,118$20,770
Q2 2015Viking Global InvestorsSell-3,537,7404,968,956$1,085,021

Frequently asked questions about ILMN activity

  • Which institutional owners are buying ILMN?

    Institutional owners buying ILMN include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in ILMN activity?

    "Buy" means an investor increased their reported position in ILMN compared to the prior reporting period. This reflects growing exposure to ILLUMINA INC (ILMN) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in ILMN increasing?

    Institutional interest in ILMN can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.