IONIS PHARMACEUTICALS INC IONS
COM · Common Stock · CUSIP 462222100 · ISIN US4622221004
American pharmaceutical company
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersCarlsbad, CA
- Founded1989
- Websiteionispharma.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($11.4m this quarter). Holder counts are more reliable. Shares outstanding: 159.4m as of 2025-07-24, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $39.52. Options: 14 managers hold calls ($65.2m notional), 14 hold puts ($34.9m).
Trends to Q2 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 350 |
| Q4 2022 | 339 |
| Q1 2023 | 316 |
| Q2 2023 | 307 |
| Q3 2023 | 313 |
| Q4 2023 | 366 |
| Q1 2024 | 362 |
| Q2 2024 | 358 |
| Q3 2024 | 357 |
| Q4 2024 | 359 |
| Q1 2025 | 348 |
| Q2 2025 | 366 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2023 | 138 | 129 |
| Q4 2023 | 175 | 143 |
| Q1 2024 | 169 | 179 |
| Q2 2024 | 168 | 182 |
| Q3 2024 | 176 | 159 |
| Q4 2024 | 160 | 169 |
| Q1 2025 | 150 | 184 |
| Q2 2025 | 197 | 169 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2024 | $38.0m | $25.2m | 0.66 |
| Q4 2024 | $26.1m | $30.9m | 1.18 |
| Q1 2025 | $24.8m | $18.8m | 0.76 |
| Q2 2025 | $65.2m | $34.9m | 0.54 |
Biggest buyers
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Added | +2.7m |
| MILLENNIUM MANAGEMENT LLC | Added | +2.0m |
| Polar Capital Holdings Plc | New | +1.0m |
| ROYAL BANK OF CANADA | Added | +983.7k |
| Balyasny Asset Management L.P. | New | +768.6k |
| Woodline Partners LP | New | +732.8k |
| TWO SIGMA ADVISERS, LP | Added | +575.6k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | New | +519.2k |
| Vestal Point Capital, LP | New | +500.0k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | Added | +477.4k |
Biggest sellers
| ORBIMED ADVISORS LLC | Sold out | -2.5m |
| WELLINGTON MANAGEMENT GROUP LLP | Reduced | -2.1m |
| CITADEL ADVISORS LLC | Reduced | -2.0m |
| Camber Capital Management LP | Sold out | -725.0k |
| Invesco Ltd. | Reduced | -618.6k |
| NORGES BANK | Reduced | -408.0k |
| BlackRock, Inc. | Reduced | -367.5k |
| UBS Group AG | Reduced | -361.3k |
| BAKER BROS. ADVISORS LP | Sold out | -357.9k |
| STATE STREET CORP | Reduced | -314.7k |
Biggest calls
| Caption Management, LLC | Added | $24.5m620.7k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $17.0m430.6k shares |
| Balyasny Asset Management L.P. | Unchanged | $10.3m260.0k shares |
| CITADEL ADVISORS LLC | Added | $3.6m90.1k shares |
| SIMPLEX TRADING, LLC | Added | $3.3m84.6k shares |
| GROUP ONE TRADING LLC | Added | $1.7m43.7k shares |
| NOMURA HOLDINGS INC | Added | $1.2m30.0k shares |
| CITIGROUP INC | Reduced | $1.1m27.5k shares |
| JANE STREET GROUP, LLC | Added | $912.7k23.1k shares |
| Walleye Capital LLC | Reduced | $422.8k10.7k shares |
Biggest puts
| ROYAL BANK OF CANADA | Added | $9.9m250.0k shares |
| J. Goldman & Co LP | New | $7.5m190.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $3.8m97.3k shares |
| BARCLAYS PLC | Unchanged | $2.4m60.6k shares |
| Caption Management, LLC | Added | $2.4m60.0k shares |
| JANE STREET GROUP, LLC | Reduced | $2.3m58.2k shares |
| CITADEL ADVISORS LLC | Reduced | $2.3m57.2k shares |
| WOLVERINE ASSET MANAGEMENT LLC | Unchanged | $1.4m35.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $1.4m34.6k shares |
| NOMURA HOLDINGS INC | New | $1.2m30.0k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| Capital World Investors 13G · institution +1.7 pts · filed 2026-05-14 | 12.8% |
| BlackRock, Inc. 13G · institution filed 2025-04-17 | 5.7% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.0% |
Fell to 5% or below in the last year: T. Rowe Price Investment Management, Inc. (3.7%, 2026-05-15), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD CAPITAL MANAGEMENT LLC)
Insider purchases and sales in Q2 2025
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q3 2023 | 0 | — | 5 | $1.7m | $1.6m |
| Q4 2023 | 0 | — | 8 | $15.0m | $14.9m |
| Q1 2024 | 0 | — | 10 | $7.1m | $897.3k |
| Q2 2024 | 0 | — | 4 | $1.1m | $900.9k |
| Q3 2024 | 0 | — | 3 | $829.8k | $829.8k |
| Q4 2024 | 1 | $181.1k | 3 | $811.0k | $809.0k |
| Q1 2025 | 0 | — | 10 | $5.2m | $1.5m |
| Q2 2025 | 1 | $477.9k | 3 | $216.4k | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-05-01 | Hayden Michael R Director | Bought | $477.9k15.0k shares |
| 2025-04-16 | Baroldi Joseph EVP, Chief Business Officer | Sold | $111.6k3.9k shares |
| 2025-04-16 | Jenne Kyle EVP, Chf GL Pdt Str Ofcr | Sold | $85.5k3.0k shares |
| 2025-04-16 | Birchler Brian EVP, Corp and Development Ops | Sold | $19.3k680 shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2025
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.05% of their portfolio | 23.6m $934.1m | Added +29.4k |
| VANGUARD GROUP INC 0.01% of their portfolio | 16.7m $660.4m | Added +330.9k |
| T. Rowe Price Investment Management, Inc. 0.40% of their portfolio | 16.0m $634.1m | Reduced -126.8k |
| Capital World Investors 0.07% of their portfolio | 12.5m $495.5m | Added +178.2k |
| BlackRock, Inc. 0.01% of their portfolio | 10.9m $430.5m | Reduced -367.5k |
| Bellevue Group AG 6.84% of their portfolio | 7.9m $310.3m | Unchanged |
| WELLINGTON MANAGEMENT GROUP LLP 0.05% of their portfolio | 6.3m $250.7m | Reduced -2.1m |
| Deep Track Capital, LP 6.21% of their portfolio | 4.9m $193.3m | Added +327.3k |
| STATE STREET CORP 0.01% of their portfolio | 4.5m $179.0m | Reduced -314.7k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.25% of their portfolio | 3.8m $150.1m | Added +2.7m |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 3.1m $123.5m | Reduced -139.0k |
| Tweedy, Browne Co LLC 10.60% of their portfolio | 2.9m $114.3m | Reduced -91.6k |
| GEODE CAPITAL MANAGEMENT, LLC 0.01% of their portfolio | 2.9m $114.2m | Added +48.1k |
| TWO SIGMA ADVISERS, LP 0.22% of their portfolio | 2.7m $105.4m | Added +575.6k |
| MILLENNIUM MANAGEMENT LLC 0.09% of their portfolio | 2.6m $104.7m | Added +2.0m |
| BVF INC/IL 2.70% of their portfolio | 1.9m $75.6m | Unchanged |
| TWO SIGMA INVESTMENTS, LP 0.13% of their portfolio | 1.8m $70.7m | Added +102.5k |
| ROYAL BANK OF CANADA 0.01% of their portfolio | 1.6m $63.2m | Added +983.7k |
| UBS Group AG 0.01% of their portfolio | 1.5m $60.4m | Reduced -361.3k |
| CITADEL ADVISORS LLC 0.05% of their portfolio | 1.5m $59.1m | Reduced -2.0m |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.01% of their portfolio | 1.5m $58.8m | Added +44.2k |
| MACQUARIE GROUP LTD 0.07% of their portfolio | 1.4m $56.7m | Reduced -233.1k |
| MORGAN STANLEY 0.00% of their portfolio | 1.4m $53.8m | Added +218.0k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.13% of their portfolio | 1.4m $53.4m | Added +154.5k |
| TD Asset Management Inc 0.04% of their portfolio | 1.1m $43.6m | Added +4.2k |
| Polar Capital Holdings Plc 0.21% of their portfolio | 1.0m $39.5m | New |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 995.9k $39.3m | Added +228.5k |
| ARK Investment Management LLC 0.26% of their portfolio | 900.3k $35.6m | Reduced -100.2k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.12% of their portfolio | 854.6k $33.8m | Added +477.4k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 814.2k $32.2m | Reduced -20.6k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.01% of their portfolio | 791.1k $31.3m | Added +131.6k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 777.9k $30.7m | Added +125.4k |
| Balyasny Asset Management L.P. 0.07% of their portfolio | 768.6k $30.4m | New |
| Hudson Bay Capital Management LP 0.19% of their portfolio | 750.0k $29.6m | Reduced -299.9k |
| Woodline Partners LP 0.15% of their portfolio | 732.8k $29.0m | New |
| Candriam S.C.A. 0.17% of their portfolio | 724.7k $28.6m | Reduced -269.0k |
| TEACHER RETIREMENT SYSTEM OF TEXAS 0.11% of their portfolio | 668.3k $26.4m | Added +167.8k |
| GROUPAMA ASSET MANAGMENT 0.44% of their portfolio | 661.0k $26.3m | Added +91.7k |
| Pictet Asset Management Holding SA 0.02% of their portfolio | 608.6k $24.2m | Reduced -9.9k |
| Eversept Partners, LP 2.34% of their portfolio | 588.9k $23.3m | Added +71.9k |
| BARCLAYS PLC 0.01% of their portfolio | 583.3k $23.0m | Added +229.3k |
| AXA S.A. 0.06% of their portfolio | 566.9k $22.4m | Added +397 |
| Bank of New York Mellon Corp 0.00% of their portfolio | 527.2k $20.8m | Reduced -17.4k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.01% of their portfolio | 519.2k $20.5m | New |
| GROUPAMA ASSET MANAGMENT 0.01% of their portfolio | 500.0k $527.4k | Unchanged |
| GREAT POINT PARTNERS LLC 12.84% of their portfolio | 500.0k $19.8m | Added +250.0k |
| Vestal Point Capital, LP 1.04% of their portfolio | 500.0k $19.8m | New |
| PINNACLE ASSOCIATES LTD 0.28% of their portfolio | 494.5k $19.5m | Reduced -114.0k |
| BANK OF MONTREAL /CAN/ 0.01% of their portfolio | 483.3k $19.1m | Reduced -299.5k |
| AMERICAN CENTURY COMPANIES INC 0.01% of their portfolio | 472.7k $18.7m | Added +356.0k |
| NORGES BANK 0.00% of their portfolio | 450.3k $17.8m | Reduced -408.0k |
| C WorldWide Group Holding A/S 0.24% of their portfolio | 450.0k $17.8m | Added +50.0k |
| Schonfeld Strategic Advisors LLC 0.13% of their portfolio | 449.2k $17.7m | Reduced -111.2k |
| GW&K Investment Management, LLC 0.16% of their portfolio | 448.8k $17.7m | Added +266.5k |
| Aberdeen Group plc 0.03% of their portfolio | 406.7k $16.2m | Reduced -39.5k |
| Legal & General Group Plc 0.00% of their portfolio | 404.4k $16.0m | Added +65.9k |
| GREAT LAKES ADVISORS, LLC 0.13% of their portfolio | 399.6k $15.8m | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 395.0k $15.6m | Reduced -26.5k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 368.1k $14.5m | Added +7.9k |
| Artisan Partners Limited Partnership 0.02% of their portfolio | 355.0k $14.0m | Added +151.8k |
| CITIGROUP INC 0.01% of their portfolio | 341.0k $13.5m | Reduced -85.5k |
| Sovran Advisors, LLC 1.39% of their portfolio | 321.9k $13.3m | Reduced -7.0k |
| Point72 Asset Management, L.P. 0.03% of their portfolio | 292.6k $11.6m | Added +5.4k |
| Swiss National Bank 0.01% of their portfolio | 288.6k $11.4m | Added +13.3k |
| SECTOR GAMMA AS 3.69% of their portfolio | 285.8k $11.3m | Unchanged |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 270.7k $10.7m | Added +117.2k |
| Privium Fund Management B.V. 2.31% of their portfolio | 267.6k $10.7m | Unchanged |
| Connor, Clark & Lunn Investment Management Ltd. 0.04% of their portfolio | 265.8k $10.5m | Added +136.5k |
| Invesco Ltd. 0.00% of their portfolio | 256.2k $10.1m | Reduced -618.6k |
| Nuveen, LLC 0.00% of their portfolio | 245.1k $9.7m | Reduced -63.7k |
| Corient Private Wealth LP 0.01% of their portfolio | 237.8k $9.4m | Added +707 |
| Verition Fund Management LLC 0.05% of their portfolio | 232.7k $9.2m | Added +180.4k |
| Orion Investment Co 3.04% of their portfolio | 217.4k $8.6m | Added +2.1k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 210.6k $8.3m | Added +61.9k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 209.9k $8.3m | Reduced -46.4k |
| California Public Employees Retirement System 0.01% of their portfolio | 202.0k $8.0m | Added +11.0k |
| EDMOND DE ROTHSCHILD HOLDING S.A. 0.12% of their portfolio | 197.6k $7.8m | Added +73.4k |
| STIFEL FINANCIAL CORP 0.01% of their portfolio | 196.4k $7.8m | Reduced -4.6k |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.11% of their portfolio | 187.3k $7.4m | Reduced -50 |
| Sicart Associates LLC 2.56% of their portfolio | 185.3k $7.3m | Reduced -350 |
| Rhenman & Partners Asset Management AB 0.91% of their portfolio | 182.0k $7.2m | Added +101.0k |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 181.6k $7.2m | Reduced -6.6k |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 177.8k $7.0m | Reduced -130.5k |
| Sonora Investment Management Group, LLC 0.48% of their portfolio | 163.2k $6.4m | Added +9.0k |
| Alyeska Investment Group, L.P. 0.02% of their portfolio | 159.0k $6.3m | New |
| Aquatic Capital Management LLC 0.13% of their portfolio | 158.1k $6.2m | Added +1.9k |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.01% of their portfolio | 153.9k $6.1m | Added +1.6k |
| BLB&B Advisors, LLC 0.28% of their portfolio | 151.6k $6.0m | Reduced -650 |
| TANG CAPITAL MANAGEMENT LLC 0.30% of their portfolio | 150.0k $5.9m | Unchanged |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.01% of their portfolio | 149.8k $5.9m | Added +6.0k |
| ADAR1 Capital Management, LLC 0.95% of their portfolio | 148.5k $5.9m | New |
| J. Goldman & Co LP 0.18% of their portfolio | 147.7k $5.8m | Reduced -160.1k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 145.1k $5.7m | Added +12.9k |
| Rafferty Asset Management, LLC 0.02% of their portfolio | 144.8k $5.7m | Reduced -31.5k |
| Sumitomo Mitsui Trust Group, Inc. 0.00% of their portfolio | 139.7k $5.5m | Reduced -2.7k |
| Amova Asset Management Americas, Inc. 0.06% of their portfolio | 139.7k $5.5m | Reduced -2.7k |
| Squarepoint Ops LLC 0.01% of their portfolio | 134.4k $5.3m | Reduced -171.0k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.12% of their portfolio | 132.0k $5.2m | Reduced -18.4k |
| Trexquant Investment LP 0.06% of their portfolio | 128.9k $5.1m | New |
| Exome Asset Management LLC 4.07% of their portfolio | 121.1k $4.8m | Reduced -14.5k |