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 ($29.7m this quarter). Holder counts are more reliable. Shares outstanding: 165.3m as of 2026-04-23, 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 ≈ $75.12. Options: 21 managers hold calls ($141.4m notional), 17 hold puts ($144.3m).
Trends to Q1 2026
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 |
| Q3 2025 | 439 |
| Q4 2025 | 494 |
| Q1 2026 | 497 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 168 | 182 |
| Q3 2024 | 176 | 159 |
| Q4 2024 | 160 | 169 |
| Q1 2025 | 150 | 184 |
| Q2 2025 | 197 | 169 |
| Q3 2025 | 245 | 152 |
| Q4 2025 | 261 | 186 |
| Q1 2026 | 241 | 223 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $65.2m | $34.9m | 0.54 |
| Q3 2025 | $171.8m | $74.8m | 0.44 |
| Q4 2025 | $149.5m | $102.3m | 0.68 |
| Q1 2026 | $141.4m | $144.3m | 1.02 |
Biggest buyers
| Capital World Investors | Added | +3.2m |
| TWO SIGMA INVESTMENTS, LP | Added | +3.2m |
| ROYAL BANK OF CANADA | Added | +2.7m |
| MILLENNIUM MANAGEMENT LLC | Added | +958.2k |
| Artisan Partners Limited Partnership | Added | +876.9k |
| GOLDMAN SACHS GROUP INC | Added | +843.9k |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +835.5k |
| PERCEPTIVE ADVISORS LLC | New | +504.0k |
| FMR LLC | Added | +484.5k |
| NEUBERGER BERMAN GROUP LLC | Added | +335.2k |
Biggest sellers
| T. Rowe Price Investment Management, Inc. | Reduced | -8.7m |
| TWO SIGMA ADVISERS, LP | Sold out | -3.1m |
| Bellevue Group AG | Reduced | -3.0m |
| CITADEL ADVISORS LLC | Reduced | -1.2m |
| NOMURA HOLDINGS INC | Reduced | -734.7k |
| Tri Locum Partners LP | Sold out | -557.2k |
| BARCLAYS PLC | Reduced | -553.0k |
| Polar Capital Holdings Plc | Reduced | -503.9k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. | Reduced | -445.3k |
| Amundi | Reduced | -437.0k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $56.8m755.8k shares |
| JANE STREET GROUP, LLC | Added | $21.7m288.7k shares |
| JPMORGAN CHASE & CO | New | $12.0m165.0k shares |
| CITADEL ADVISORS LLC | Added | $8.7m115.3k shares |
| Ikarian Capital, LLC | Added | $8.4m112.1k shares |
| CITIGROUP INC | Added | $7.4m98.4k shares |
| NOMURA HOLDINGS INC | Reduced | $4.5m59.4k shares |
| SIG BROKERAGE, LP | New | $4.1m55.0k shares |
| IMC-Chicago, LLC | Added | $3.8m50.8k shares |
| BOOTHBAY FUND MANAGEMENT, LLC | Added | $2.4m31.6k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $34.1m454.3k shares |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC | Added | $33.8m450.0k shares |
| JANE STREET GROUP, LLC | Added | $21.0m279.8k shares |
| CITADEL ADVISORS LLC | Added | $18.6m248.3k shares |
| JPMORGAN CHASE & CO | New | $12.0m165.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $4.8m63.9k shares |
| LMR Partners LLP | Added | $3.9m51.4k shares |
| BARCLAYS PLC | Reduced | $3.8m50.0k shares |
| WOLVERINE ASSET MANAGEMENT LLC | Unchanged | $2.6m35.0k shares |
| SIG BROKERAGE, LP | New | $2.3m30.0k 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 Q1 2026
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 |
|---|---|---|---|---|---|
| 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 | — |
| Q3 2025 | 0 | — | 14 | $42.6m | $29.3m |
| Q4 2025 | 0 | — | 12 | $26.8m | $23.7m |
| Q1 2026 | 0 | — | 15 | $75.8m | $57.6m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-19 | Schneider Eugene EVP, Chf Clinical Develop Ofcr | Sold plan | $412.5k5.8k shares |
| 2026-03-17 | HOUGEN ELIZABETH L EVP, Finance & CFO | Sold plan | $744.7k10.2k shares |
| 2026-03-16 | HOUGEN ELIZABETH L EVP, Finance & CFO | Sold plan | $15.6m215.0k shares |
| 2026-03-10 | Jenne Kyle EVP, Chf GL Pdt Str Ofcr | Sold plan | $2.8m37.3k shares |
| 2026-03-10 | Monia Brett P Chief Executive Officer, director | Sold plan | $2.6m34.1k shares |
| 2026-03-09 | Monia Brett P Chief Executive Officer, director | Sold plan | $9.5m126.7k shares |
| 2026-03-09 | O'NEIL PATRICK R. EVP CLO & General Counsel | Sold plan | $763.6k10.1k shares |
| 2026-03-04 | Baroldi Joseph EVP, Chief Business Officer · by Spouse | Sold plan | $19.0k238 shares |
| 2026-03-04 | Baroldi Joseph EVP, Chief Business Officer | Sold plan | $16.1k201 shares |
| 2026-03-04 | LOSCALZO JOSEPH Director | Sold plan | $16.0k200 shares |
| 2026-03-03 | BENNETT C FRANK EVP, Chief Scientific Officer | Sold plan | $6.7m85.1k shares |
| 2026-03-03 | Diaz Allene M. Director | Sold plan | $4.4m54.9k shares |
| 2026-03-03 | KLEIN JOSEPH III Director | Sold plan | $1.7m21.3k shares |
| 2026-03-03 | Devers Shannon L. EVP, Chief Human Resources Ofc | Sold plan | $1.6m20.1k shares |
| 2026-03-03 | Baroldi Joseph EVP, Chief Business Officer | Sold plan | $325.1k4.1k shares |
| 2026-03-03 | Baroldi Joseph EVP, Chief Business Officer · by Spouse | Sold plan | $170.8k2.1k shares |
| 2026-03-03 | LOSCALZO JOSEPH Director | Sold plan | $66.8k832 shares |
| 2026-02-13 | Swayze Eric EVP Research | Sold plan | $1.3m15.6k shares |
| 2026-02-11 | PARSHALL B LYNNE Director | Sold plan | $413.6k5.0k shares |
| 2026-02-06 | Monia Brett P Chief Executive Officer, director | Sold plan | $2.5m29.4k shares |
| 2026-01-30 | Monia Brett P Chief Executive Officer, director | Sold | $5.2m63.0k shares |
| 2026-01-30 | HOUGEN ELIZABETH L EVP, Finance & CFO | Sold | $581.7k7.0k shares |
| 2026-01-30 | O'NEIL PATRICK R. EVP CLO & General Counsel | Sold | $516.1k6.2k shares |
| 2026-01-30 | Schneider Eugene EVP, Chf Clinical Develop Ofcr | Sold | $515.6k6.2k shares |
| 2026-01-30 | Birchler Brian EVP, Corp and Development Ops | Sold | $513.0k6.2k shares |
| 2026-01-30 | Swayze Eric EVP Research | Sold | $512.4k6.2k shares |
| 2026-01-30 | BENNETT C FRANK EVP, Chief Scientific Officer | Sold | $488.2k5.9k shares |
| 2026-01-30 | Baroldi Joseph EVP, Chief Business Officer | Sold | $439.4k5.3k shares |
| 2026-01-22 | Devers Shannon L. EVP, Chief Human Resources Ofc | Sold plan | $323.5k4.0k shares |
| 2026-01-16 | Monia Brett P Chief Executive Officer, director | Sold | $3.3m44.0k shares |
The latest 30 of 44 trades.
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, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.10% of their portfolio | 24.6m $1.8bn | Added +484.5k |
| Capital World Investors 0.22% of their portfolio | 21.2m $1.6bn | Added +3.2m |
| BlackRock, Inc. 0.01% of their portfolio | 10.4m $784.1m | Reduced -205.4k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.03% of their portfolio | 7.8m $586.4m | First filing |
| VANGUARD CAPITAL MANAGEMENT LLC 0.01% of their portfolio | 7.1m $534.5m | First filing |
| WELLINGTON MANAGEMENT GROUP LLP 0.09% of their portfolio | 6.4m $480.0m | Added +131.5k |
| T. Rowe Price Investment Management, Inc. 0.32% of their portfolio | 6.2m $462.5m | Reduced -8.7m |
| TWO SIGMA INVESTMENTS, LP 0.37% of their portfolio | 5.9m $439.8m | Added +3.2m |
| STATE STREET CORP 0.01% of their portfolio | 4.0m $300.0m | Added +20.7k |
| GEODE CAPITAL MANAGEMENT, LLC 0.02% of their portfolio | 4.0m $305.2m | Added +835.5k |
| ROYAL BANK OF CANADA 0.05% of their portfolio | 3.8m $285.5m | Added +2.7m |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.03% of their portfolio | 3.0m $227.2m | Added +37.4k |
| JPMORGAN CHASE & CO 0.01% of their portfolio | 2.4m $171.4m | Added +58.8k |
| Tweedy, Browne Co LLC 13.57% of their portfolio | 2.3m $170.9m | Reduced -189.3k |
| Artisan Partners Limited Partnership 0.25% of their portfolio | 2.1m $154.6m | Added +876.9k |
| BAKER BROS. ADVISORS LP 0.88% of their portfolio | 2.0m $153.8m | Added +255.9k |
| DEERFIELD MANAGEMENT COMPANY, L.P. 1.75% of their portfolio | 2.0m $148.7m | Unchanged |
| Deep Track Capital, LP 3.02% of their portfolio | 1.9m $146.4m | Added +250.0k |
| Bellevue Group AG 3.25% of their portfolio | 1.8m $136.6m | Reduced -3.0m |
| GOLDMAN SACHS GROUP INC 0.02% of their portfolio | 1.7m $127.6m | Added +843.9k |
| AMERICAN CENTURY COMPANIES INC 0.06% of their portfolio | 1.7m $124.9m | Added +46.7k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.02% of their portfolio | 1.6m $118.9m | Added +41.4k |
| FRANKLIN RESOURCES INC 0.03% of their portfolio | 1.6m $118.3m | Added +253.7k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.02% of their portfolio | 1.5m $110.8m | Added +87.1k |
| Pictet Asset Management Holding SA 0.11% of their portfolio | 1.4m $107.1m | Added +16.5k |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC 4.88% of their portfolio | 1.4m $105.4m | Reduced -58.7k |
| Invesco Ltd. 0.01% of their portfolio | 1.3m $95.9m | Added +8.1k |
| MILLENNIUM MANAGEMENT LLC 0.06% of their portfolio | 1.1m $79.0m | Added +958.2k |
| MORGAN STANLEY 0.00% of their portfolio | 1.0m $77.1m | Added +6.6k |
| VANGUARD FIDUCIARY TRUST CO 0.02% of their portfolio | 1.0m $76.9m | First filing |
| CITADEL ADVISORS LLC 0.05% of their portfolio | 942.5k $70.8m | Reduced -1.2m |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.08% of their portfolio | 907.5k $68.1m | Reduced -445.3k |
| Connor, Clark & Lunn Investment Management Ltd. 0.15% of their portfolio | 874.1k $65.6m | Reduced -202.3k |
| NORTHERN TRUST CORP 0.01% of their portfolio | 868.2k $65.2m | Added +21.5k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 840.6k $63.1m | Added +57.0k |
| Polar Capital Holdings Plc 0.27% of their portfolio | 829.5k $62.3m | Reduced -503.9k |
| GROUPAMA ASSET MANAGMENT 0.90% of their portfolio | 824.5k $61.9m | Added +57.7k |
| UBS Group AG 0.01% of their portfolio | 808.4k $60.7m | Reduced -236.6k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.10% of their portfolio | 785.3k $59.0m | Reduced -79.6k |
| GW&K Investment Management, LLC 0.52% of their portfolio | 779.3k $58.5m | Reduced -7.3k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.03% of their portfolio | 737.9k $55.4m | Reduced -325.5k |
| Squarepoint Ops LLC 0.11% of their portfolio | 695.3k $52.2m | Added +259.0k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.20% of their portfolio | 672.9k $50.5m | Added +87.9k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.02% of their portfolio | 666.1k $50.0m | Reduced -146.6k |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 660.1k $49.6m | Added +61.4k |
| Nuveen, LLC 0.01% of their portfolio | 648.5k $48.7m | Reduced -12.3k |
| Eversept Partners, LP 3.13% of their portfolio | 632.1k $47.5m | Added +93.9k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.71% of their portfolio | 575.0k $43.2m | Unchanged |
| TD Asset Management Inc 0.03% of their portfolio | 530.0k $39.8m | Reduced -243.2k |
| TEACHER RETIREMENT SYSTEM OF TEXAS 0.16% of their portfolio | 523.9k $39.3m | Added +101.0k |
| Bank of New York Mellon Corp 0.01% of their portfolio | 514.6k $38.6m | Reduced -23.3k |
| PERCEPTIVE ADVISORS LLC 0.75% of their portfolio | 504.0k $37.8m | New |
| BOONE CAPITAL MANAGEMENT LLC 11.51% of their portfolio | 500.5k $37.6m | Added +82.7k |
| Candriam S.C.A. 0.19% of their portfolio | 484.1k $36.3m | Reduced -193.6k |
| BNP PARIBAS FINANCIAL MARKETS 0.02% of their portfolio | 479.5k $36.0m | Added +144.9k |
| Alyeska Investment Group, L.P. 0.10% of their portfolio | 473.1k $35.5m | Reduced -8.6k |
| FIRST TRUST ADVISORS LP 0.03% of their portfolio | 468.4k $35.2m | Reduced -56.9k |
| NEUBERGER BERMAN GROUP LLC 0.03% of their portfolio | 443.3k $33.3m | Added +335.2k |
| PINNACLE ASSOCIATES LTD 0.42% of their portfolio | 436.5k $32.8m | Reduced -25.5k |
| D. E. Shaw & Co., Inc. 0.03% of their portfolio | 429.6k $32.3m | Added +96.8k |
| ALLIANCEBERNSTEIN L.P. 0.01% of their portfolio | 400.7k $31.7m | Added +58.8k |
| Davern Capital Partners, LP 7.97% of their portfolio | 386.9k $29.1m | Added +148.4k |
| C WorldWide Group Holding A/S 0.59% of their portfolio | 366.0k $27.5m | Unchanged |
| NEW YORK STATE COMMON RETIREMENT FUND 0.04% of their portfolio | 350.4k $26.3m | Added +108.6k |
| Capital Research Global Investors 0.00% of their portfolio | 323.0k $24.3m | New |
| RENAISSANCE TECHNOLOGIES LLC 0.04% of their portfolio | 305.5k $22.9m | Added +81.9k |
| Swiss National Bank 0.01% of their portfolio | 304.5k $22.9m | Added +6.0k |
| Hudson Bay Capital Management LP 0.13% of their portfolio | 295.1k $22.2m | Reduced -179.9k |
| Legal & General Group Plc 0.01% of their portfolio | 294.7k $22.1m | Reduced -30.5k |
| Privium Fund Management B.V. 4.53% of their portfolio | 290.0k $21.8m | Added +49.2k |
| BARCLAYS PLC 0.01% of their portfolio | 289.9k $21.8m | Reduced -553.0k |
| ARK Investment Management LLC 0.17% of their portfolio | 288.7k $21.7m | Reduced -134.3k |
| TimesSquare Capital Management, LLC 0.35% of their portfolio | 275.7k $20.7m | New |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 267.2k $20.1m | Added +91.2k |
| California Public Employees Retirement System 0.01% of their portfolio | 255.5k $19.2m | Added +42.1k |
| HRT FINANCIAL LP 0.07% of their portfolio | 252.2k $18.9m | Added +229.3k |
| Zurich Insurance Group Ltd/FI 0.14% of their portfolio | 239.6k $18.0m | Reduced -22.2k |
| DAVENPORT & Co LLC 0.10% of their portfolio | 238.2k $17.9m | Added +20.3k |
| J. Goldman & Co LP 0.82% of their portfolio | 235.3k $17.7m | Added +167.6k |
| RAYMOND JAMES FINANCIAL INC 0.01% of their portfolio | 235.1k $17.7m | Reduced -22.1k |
| ExodusPoint Capital Management, LP 0.17% of their portfolio | 227.1k $17.1m | Added +143.2k |
| Orion Investment Co 5.36% of their portfolio | 225.0k $16.9m | Reduced -146 |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.03% of their portfolio | 219.7k $16.5m | Added +78 |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.24% of their portfolio | 219.2k $16.5m | Added +15.5k |
| Handelsbanken Fonder AB 0.05% of their portfolio | 213.9k $16.1m | Added +166.0k |
| Trexquant Investment LP 0.12% of their portfolio | 213.6k $16.0m | Added +81.4k |
| Jump Financial, LLC 0.23% of their portfolio | 206.7k $15.5m | New |
| STIFEL FINANCIAL CORP 0.01% of their portfolio | 196.7k $14.8m | Reduced -2.2k |
| Corient Private Wealth LP 0.02% of their portfolio | 196.6k $14.8m | Reduced -234.8k |
| JANE STREET GROUP, LLC 0.02% of their portfolio | 191.8k $14.4m | Added +161.3k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 189.9k $14.3m | Reduced -90.2k |
| HSBC HOLDINGS PLC 0.01% of their portfolio | 186.0k $14.0m | Added +132.1k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 176.5k $13.3m | Added +32.3k |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 173.4k $13.0m | Reduced -1.9k |
| SECTOR GAMMA AS 3.00% of their portfolio | 169.5k $12.7m | Reduced -15.5k |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main 0.01% of their portfolio | 167.7k $12.6m | Unchanged |
| Focus Partners Wealth 0.01% of their portfolio | 165.5k $12.4m | Reduced -16.3k |
| ADAR1 Capital Management, LLC 0.72% of their portfolio | 160.3k $12.0m | Added +13.2k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 159.9k $12.0m | Added +10.4k |
| Sicart Associates LLC 3.07% of their portfolio | 159.4k $12.0m | Reduced -4.1k |