IONIS PHARMACEUTICALS INC (IONS) Institutional Ownership Changes & 13F Activity

IONIS PHARMACEUTICALS INC (IONS) institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC 13F filings (Q1 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions among tracked filers. Notable filers include Tweedy, Browne Co All Funds (US), ARK Invest, and Renaissance Technologies LLC.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q1 2026Tweedy, Browne Co All Funds (US)Sell-189,3052,275,625$170,876,681
Q1 2026ARK InvestSell-134,252288,716$21,679,720
Q1 2026Renaissance Technologies LLCBuy81,942305,549$22,943,674
Q4 2025Tweedy, Browne Co All Funds (US)Sell-436,2862,464,930$195,000,612
Q4 2025Renaissance Technologies LLCSell-263,107223,607$17,689,550
Q4 2025ARK InvestSell-208,247422,968$33,461,022
Q3 2025ARK InvestSell-269,103631,215$41,294,081
Q3 2025Renaissance Technologies LLCBuy216,000486,714$31,840,830
Q3 2025Tweedy, Browne Co All Funds (US)Buy9,2682,901,216$189,797,551
Q2 2025Renaissance Technologies LLCBuy117,200270,714$10,695,910
Q2 2025ARK InvestSell-100,209900,318$35,571,574
Q2 2025Tweedy, Browne Co All Funds (US)Sell-91,5702,891,948$114,260,865
Q1 2025Tweedy, Browne Co All Funds (US)Sell-265,3452,983,518$90,012,738
Q1 2025Renaissance Technologies LLCSell-52,000153,514$4,631,517
Q1 2025ARK InvestSell-24,7331,000,527$30,185,886
Q4 2024ARK InvestSell-359,0091,025,260$35,843,086
Q4 2024Tweedy, Browne Co All Funds (US)Sell-205,8133,248,863$113,580,250
Q4 2024Renaissance Technologies LLCBuy15,000205,514$7,184,769
Q3 2024Renaissance Technologies LLCSell-59,000190,514$7,631,991
Q3 2024ARK InvestBuy23,2441,384,269$55,453,818
Q2 2024Renaissance Technologies LLCBuy69,800249,514$11,891,837
Q2 2024ARK InvestSell-38,8271,361,025$64,866,465
Q1 2024ARK InvestSell-505,2041,399,852$60,683,587
Q1 2024Renaissance Technologies LLCBuy67,300179,714$7,791
Q4 2023ARK InvestSell-461,3111,905,056$96,376,805
Q4 2023Renaissance Technologies LLCSell-157,386112,414$5,687
Q4 2023Tweedy, Browne Co All Funds (US)Sell-55,4973,454,676$174,772,059
Q3 2023Renaissance Technologies LLCSell-100,700269,800$12,238
Q3 2023ARK InvestSell-56,2642,366,367$107,338,401
Q3 2023Tweedy, Browne Co All Funds (US)Sell-30,6853,510,173$159,221,447

Frequently asked questions about IONS activity

  • Which institutional owners are buying IONS?

    Institutional owners buying IONS 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 IONS activity?

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

  • Is institutional interest in IONS increasing?

    Institutional interest in IONS 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.

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