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Ionis Pharmaceuticals Inc

IONS
Exchange
Nasdaq
Industry
Pharmaceutical Preparations
SEC CIK
0000874015

In the last 90 days, Ionis Pharmaceuticals Inc insiders filed 1 open-market purchase and 4 sales; 515 institutions reported holding it in 13F filings for Q2 2026, worth $14.3B in total; ARK Invest is the only superinvestor holding it.

13F holders, Q4 2025

Institutional positions in Ionis Pharmaceuticals Inc as of Dec 31, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Institutional holders
494
+68 vs. Q3 2025
Shares held
170.2M
+2.78M (+1.7%) vs. Q3 2025
Total value
$13.5B
+$2.50B (+22.8%) vs. Q3 2025
New holders
112
167 more added
Sold out
44
142 more reduced

11 institutions that held it in Q3 2025 haven't filed for Q4 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q3 2025: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting IONS on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holdersQ4 2025: 494 institutions
Q1 2021: 365 institutionsQ2 2021: 338 institutionsQ3 2021: 326 institutionsQ4 2021: 341 institutionsQ1 2022: 333 institutionsQ2 2022: 351 institutionsQ3 2022: 350 institutionsQ4 2022: 339 institutionsQ1 2023: 315 institutionsQ2 2023: 305 institutionsQ3 2023: 312 institutionsQ4 2023: 365 institutionsQ1 2024: 361 institutionsQ2 2024: 357 institutionsQ3 2024: 354 institutionsQ4 2024: 356 institutionsQ1 2025: 344 institutionsQ2 2025: 363 institutionsQ3 2025: 437 institutionsQ4 2025: 494 institutionsQ1 2026: 497 institutionsQ2 2026: 515 institutions
Value heldQ4 2025: $13.5B
Q1 2021: $5.55BQ2 2021: $4.96BQ3 2021: $4.08BQ4 2021: $3.75BQ1 2022: $4.63BQ2 2022: $4.61BQ3 2022: $5.59BQ4 2022: $4.93BQ1 2023: $4.69BQ2 2023: $5.60BQ3 2023: $6.35BQ4 2023: $7.21BQ1 2024: $6.17BQ2 2024: $6.83BQ3 2024: $6.31BQ4 2024: $5.61BQ1 2025: $5.03BQ2 2025: $6.67BQ3 2025: $11.0BQ4 2025: $13.5BQ1 2026: $13.0BQ2 2026: $14.3B
Institutions holding IONS and their total value by quarter
QuarterHoldersValue
Q2 2026515$14.3B
Q1 2026497$13.0B
Q4 2025494$13.5B
Q3 2025437$11.0B
Q2 2025363$6.67B
Q1 2025344$5.03B
Q4 2024356$5.61B
Q3 2024354$6.31B
Q2 2024357$6.83B
Q1 2024361$6.17B
Q4 2023365$7.21B
Q3 2023312$6.35B
Q2 2023305$5.60B
Q1 2023315$4.69B
Q4 2022339$4.93B
Q3 2022350$5.59B
Q2 2022351$4.61B
Q1 2022333$4.63B
Q4 2021341$3.75B
Q3 2021326$4.08B
Q2 2021338$4.96B
Q1 2021365$5.55B

Institutions, Q4 2025

Shares, value and share of portfolio for each institution holding Ionis Pharmaceuticals Inc; share changes are against Q3 2025.

Institutions holding IONS in Q4 2025
InstitutionSharesValue% of portfolioChange in sharesAction
FMR LLC24,072,101$1.90B0.10%+383,063+1.6%Added
Capital World Investors17,961,299$1.42B0.19%+5,238,571+41.2%Added
Vanguard Group Inc16,440,459$1.30B0.02%−41,271−0.3%Reduced
BlackRock, Inc.10,647,863$842.4M0.01%+199,923+1.9%Added
T. Rowe Price Investment Management, Inc.9,108,019$720.5M0.45%−4,048,910−30.8%Reduced
Wellington Management Group LLP6,260,325$495.3M0.09%−328,486−5.0%Reduced
Bellevue Group AG4,802,199$379.9M7.20%−1,442,252−23.1%Reduced
State Street Corp3,974,865$314.5M0.01%−413,786−9.4%Reduced
Geode Capital Management, LLC3,148,849$249.2M0.02%+82,560+2.7%Added
Two Sigma Advisers, LP3,052,111$241.5M0.47%+979,000+47.2%Added
Price T Rowe Associates Inc2,987,840$236.4M0.03%+258,155+9.5%Added
Two Sigma Investments, LP2,658,646$210.3M0.31%+1,082,703+68.7%Added
Tweedy, Browne Co LLC2,464,930$195.0M15.74%−436,286−15.0%Reduced
JPMorgan Chase & Co2,304,792$182.3M0.01%+1,760,324+323.3%Added
Citadel Advisors LLC2,134,636$168.9M0.11%−267,429−11.1%Reduced
Deerfield Management Company, L.P. (Series C)1,979,669$156.6M2.01%00.0%Unchanged
Baker Bros. Advisors LP1,791,841$141.8M0.83%+1,225,043+216.1%Added
Deep Track Capital, LP1,700,000$134.5M3.07%−2,108,144−55.4%Reduced
American Century Companies Inc1,617,106$127.9M0.06%+244,881+17.8%Added
Charles Schwab Investment Management Inc1,541,841$122.0M0.02%+21,890+1.4%Added
Summit Partners Public Asset Management, LLC1,462,706$115.7M3.26%+712,706+95.0%Added
Pictet Asset Management Holding SA1,418,491$112.5M0.11%+25,367+1.8%Added
UBS Asset Management Americas Inc1,388,567$109.8M0.02%+234,401+20.3%Added
BNP PARIBAS ASSET MANAGEMENT Holding S.A.1,352,837$107.0M0.12%+293,116+27.7%Added
Polar Capital Holdings Plc1,333,424$105.5M0.48%+299,802+29.0%Added
Franklin Resources Inc1,321,345$104.5M0.03%+1,314,752+19,941.6%Added
Invesco Ltd.1,269,290$100.4M0.01%+750,220+144.5%Added
Artisan Partners Limited Partnership1,181,416$93.5M0.14%+291,344+32.7%Added
Royal Bank of Canada1,118,797$88.5M0.02%−107,827−8.8%Reduced
Connor, Clark & Lunn Investment Management Ltd.1,076,370$85.2M0.22%+198,215+22.6%Added
Arrowstreet Capital, Limited Partnership1,063,327$84.1M0.05%+433,191+68.7%Added
UBS Group AG1,045,041$82.7M0.02%−1,949−0.2%Reduced
Morgan Stanley1,019,906$80.7M0.00%−160,410−13.6%Reduced
Nomura Asset Management International Inc.864,892$68.4M0.10%+864,892New
Goldman Sachs Group Inc855,966$67.7M0.01%+78,396+10.1%Added
Nomura Holdings Inc848,815$67.1M0.19%+115,417+15.7%Added
Northern Trust Corp846,718$67.0M0.01%+1,775+0.2%Added
Barclays PLC842,871$66.7M0.03%+128,823+18.0%Added
Massachusetts Financial Services Co812,747$64.3M0.02%−49,846−5.8%Reduced
GW&K Investment Management, LLC786,668$62.2M0.54%+522,661+198.0%Added
Bank of America Corp783,579$62.0M0.00%−71,716−8.4%Reduced
TD Asset Management Inc773,184$61.2M0.05%−187,088−19.5%Reduced
Groupama Asset Managment766,889$60.7M0.89%+205,112+36.5%Added
Candriam Luxembourg S.C.A.677,629$53.6M0.27%+66,392+10.9%Added
Nuveen, LLC660,769$52.3M0.01%+245,151+59.0%Added
Ameriprise Financial Inc598,748$47.4M0.01%−167,074−21.8%Reduced
Voloridge Investment Management, LLC584,970$46.3M0.16%−218,077−27.2%Reduced
Eventide Asset Management, LLC575,000$45.5M0.71%+575,000New
Tri Locum Partners LP557,174$44.1M5.72%+557,174New
Eversept Partners, LP538,218$42.6M2.39%−443−0.1%Reduced
Bank of New York Mellon Corp537,886$42.6M0.01%+5,772+1.1%Added
First Trust Advisors LP525,239$41.6M0.03%+450,015+598.2%Added
Alyeska Investment Group, L.P.481,711$38.1M0.11%+170,453+54.8%Added
Hudson Bay Capital Management LP475,000$37.6M0.22%−40,000−7.8%Reduced
Pinnacle Associates Ltd461,968$36.5M0.47%−19,783−4.1%Reduced
Amundi460,947$36.5M0.01%+359,416+354.0%Added
Squarepoint Ops LLC436,279$34.5M0.07%+52,487+13.7%Added
ARK Investment Management LLCSuperinvestorARK Invest422,968$33.5M0.22%−208,247−33.0%Reduced
Teacher Retirement System of Texas422,899$33.5M0.12%−51,046−10.8%Reduced
Boone Capital Management LLC417,833$33.1M10.37%00.0%Unchanged
C WorldWide Group Holding A/S366,000$29.0M0.51%−60,000−14.1%Reduced
Jain Global LLC356,259$28.2M0.28%+130,520+57.8%Added
Alliancebernstein L.P.341,849$27.0M0.01%+287,587+530.0%Added
BNP Paribas Arbitrage, SA334,608$26.5M0.02%−48,618−12.7%Reduced
D. E. Shaw & Co., Inc.332,803$26.3M0.02%−298,135−47.3%Reduced
Legal & General Group Plc325,148$25.7M0.01%+5,583+1.7%Added
Norges Bank320,160$25.3M0.00%+320,160New
Swiss National Bank298,500$23.6M0.01%+5,400+1.8%Added
Wells Fargo & Company280,045$22.2M0.00%−5,248−1.8%Reduced
Zurich Insurance Group Ltd261,820$20.7M0.14%+261,820New
Raymond James Financial Inc257,210$20.3M0.01%+16,786+7.0%Added
Marshall Wace, LLP256,933$20.3M0.02%−701,896−73.2%Reduced
New York State Common Retirement Fund241,853$19.1M0.03%+73,631+43.8%Added
Privium Fund Management B.V.240,824$19.1M3.51%−8,070−3.2%Reduced
Davern Capital Partners, LP238,477$18.9M6.10%+238,477New
Orion Investment Co225,161$17.8M5.45%+456+0.2%Added
Renaissance Technologies LLC223,607$17.7M0.03%−263,107−54.1%Reduced
Universal- Beteiligungs- und Servicegesellschaft mbH219,574$17.4M0.03%+22,140+11.2%Added
Davenport & Co LLC217,897$17.2M0.09%+155,334+248.3%Added
CI Private Wealth, LLC216,438$17.1M0.02%+209,848+3,184.3%Added
California Public Employees Retirement System213,368$16.9M0.01%−2,477−1.1%Reduced
Tocqueville Asset Management L.P.203,730$16.1M0.24%+10,685+5.5%Added
Ikarian Capital, LLC202,038$16.0M2.07%−213,125−51.3%Reduced
Stifel Financial Corp198,863$15.7M0.01%−3,765−1.9%Reduced
Sector Gamma AS184,977$14.6M3.34%−85,986−31.7%Reduced
Colony Group, LLC181,817$14.4M0.02%+181,817New
Dimensional Fund Advisors LP176,035$13.9M0.00%+133,818+317.0%Added
Rhumbline Advisers175,387$13.9M0.01%−6,674−3.7%Reduced
DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main167,657$13.3M0.01%+167,657New
Man Group plc166,042$13.1M0.03%−167,778−50.3%Reduced
Sicart Associates LLC163,557$12.9M3.43%−761−0.5%Reduced
Rhenman & Partners Asset Management AB158,500$12.5M1.17%−151,500−48.9%Reduced
CenterBook Partners LP153,949$12.2M0.60%+153,949New
Manufacturers Life Insurance Company, The153,241$12.1M0.01%+55,218+56.3%Added
Deutsche Bank AG149,443$11.8M0.00%+60,640+68.3%Added
Great Lakes Advisors, LLC149,180$11.8M0.10%−37,770−20.2%Reduced
ADAR1 Capital Management, LLC147,130$11.6M0.87%+13,312+9.9%Added
Artia Global Partners LP144,376$11.4M1.84%+84,200+139.9%Added
California State Teachers Retirement System144,173$11.4M0.01%−939−0.6%Reduced
Fisher Asset Management, LLC141,615$11.2M0.00%+135,405+2,180.4%Added