IONIS PHARMACEUTICALS INC (IONS) Stock Institutional Trading Activity


IONIS PHARMACEUTICALS INC (IONS) 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 Tweedy, Browne Co All Funds (US), Renaissance Technologies LLC, and ARK Invest. 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
Q1 2023Renaissance Technologies LLCSell-542,500636,314$22,742
Q1 2023Tweedy, Browne Co All Funds (US)Sell-903,541,046$126,557
Q4 2022ARK InvestSell-1,039,5692,673,538$100,979,530
Q4 2022Renaissance Technologies LLCBuy311,1001,178,814$44,524
Q4 2022Tweedy, Browne Co All Funds (US)Buy818,1483,541,136$133,749
Q3 2022ARK InvestSell-988,1903,713,107$164,231
Q3 2022Renaissance Technologies LLCBuy252,900867,714$38,379
Q3 2022Tweedy, Browne Co All Funds (US)Sell-3,7902,722,988$120,438
Q2 2022ARK InvestSell-1,470,0114,701,297$171,691
Q2 2022Renaissance Technologies LLCBuy479,900614,814$22,760
Q2 2022Tweedy, Browne Co All Funds (US)Sell-198,3242,726,778$100,945
Q1 2022ARK InvestSell-911,9486,171,308$228,585
Q1 2022Renaissance Technologies LLCSell-95,900134,914$4,997
Q1 2022Tweedy, Browne Co All Funds (US)Buy2,925,1022,925,102$108,346
Q4 2021ARK InvestSell-1,428,1287,083,256$215,543
Q4 2021Renaissance Technologies LLCBuy133,100230,814$7,024
Q3 2021ARK InvestSell-396,3498,511,384$285,472
Q3 2021Renaissance Technologies LLCSell-678,70097,714$3,277
Q2 2021ARK InvestBuy3,765,4628,907,733$355,329
Q2 2021Renaissance Technologies LLCBuy189,000776,414$30,971
Q1 2021ARK InvestBuy2,742,7175,142,271$231,197
Q1 2021Renaissance Technologies LLCSell-157,934587,414$26,410
Q4 2020ARK InvestBuy1,896,9942,399,554$135,671
Q4 2020Renaissance Technologies LLCSell-721,819745,348$42,142
Q3 2020ARK InvestBuy158,429502,560$23,846
Q3 2020Renaissance Technologies LLCSell-285,7001,467,167$69,617
Q2 2020ARK InvestBuy224,450344,131$20,290
Q2 2020Renaissance Technologies LLCBuy64,4561,752,867$103,349
Q1 2020ARK InvestSell-96,344119,681$5,659
Q1 2020Renaissance Technologies LLCSell-350,3001,688,411$79,828

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.