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 ($89.3m this quarter). Holder counts are more reliable. Shares outstanding: 162.0m as of 2025-10-23, 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 ≈ $79.09. Options: 25 managers hold calls ($149.5m notional), 19 hold puts ($102.3m).
Trends to Q4 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 |
| Q3 2025 | 439 |
| Q4 2025 | 494 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2024 | 169 | 179 |
| 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 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2025 | $24.8m | $18.8m | 0.76 |
| Q2 2025 | $65.2m | $34.9m | 0.54 |
| Q3 2025 | $171.8m | $74.8m | 0.44 |
| Q4 2025 | $149.5m | $102.3m | 0.68 |
Biggest buyers
| Capital World Investors | Added | +5.2m |
| T. Rowe Price Investment Management, Inc. | Added | +1.7m |
| FRANKLIN RESOURCES INC | Added | +1.3m |
| BAKER BROS. ADVISORS LP | Added | +1.2m |
| JPMORGAN CHASE & CO | Added | +1.2m |
| TWO SIGMA INVESTMENTS, LP | Added | +1.1m |
| TWO SIGMA ADVISERS, LP | Added | +979.0k |
| Invesco Ltd. | Added | +750.2k |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC | Added | +712.7k |
| EVENTIDE ASSET MANAGEMENT, LLC | New | +575.0k |
Biggest sellers
| Lombard Odier Asset Management (Europe) Ltd | Sold out | -6.5m |
| Deep Track Capital, LP | Reduced | -2.1m |
| Bellevue Group AG | Reduced | -1.4m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -1.2m |
| MACQUARIE GROUP LTD | Sold out | -1.1m |
| Vestal Point Capital, LP | Sold out | -1.1m |
| BANK OF MONTREAL /CAN/ | Reduced | -711.0k |
| MARSHALL WACE, LLP | Reduced | -701.9k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -686.3k |
| Balyasny Asset Management L.P. | Reduced | -639.5k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $41.4m523.5k shares |
| Balyasny Asset Management L.P. | Added | $20.6m260.6k shares |
| GOLDMAN SACHS GROUP INC | Unchanged | $13.2m166.3k shares |
| BARCLAYS PLC | Reduced | $10.3m129.6k shares |
| CITADEL ADVISORS LLC | Reduced | $8.7m109.4k shares |
| DIADEMA PARTNERS LP | Added | $8.4m106.2k shares |
| NOMURA HOLDINGS INC | New | $7.6m95.9k shares |
| Ikarian Capital, LLC | Added | $7.5m94.6k shares |
| Caption Management, LLC | Added | $6.7m85.0k shares |
| GROUP ONE TRADING LLC | Added | $5.0m63.2k shares |
Biggest puts
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC | New | $23.7m300.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $23.1m292.1k shares |
| BARCLAYS PLC | Unchanged | $11.6m146.9k shares |
| SIMPLEX TRADING, LLC | Added | $6.5m82.6k shares |
| JANE STREET GROUP, LLC | Added | $5.5m69.6k shares |
| CITADEL ADVISORS LLC | Reduced | $5.5m69.0k shares |
| Caption Management, LLC | Added | $4.7m60.0k shares |
| GOLDMAN SACHS GROUP INC | Reduced | $3.8m48.2k shares |
| ROYAL BANK OF CANADA | Reduced | $3.8m47.7k shares |
| WOLVERINE ASSET MANAGEMENT LLC | Unchanged | $2.8m35.0k 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 Q4 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 |
|---|---|---|---|---|---|
| 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 | — |
| Q3 2025 | 0 | — | 14 | $42.6m | $29.3m |
| Q4 2025 | 0 | — | 12 | $26.8m | $23.7m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-12-01 | WENDER JOSEPH H Director · by Trust | Sold plan | $2.3m28.0k shares |
| 2025-11-25 | Devers Shannon L. EVP, Chief Human Resources Ofc | Sold plan | $1.4m16.8k shares |
| 2025-11-25 | KLEIN JOSEPH III Director · by Trust | Sold plan | $960.0k12.0k shares |
| 2025-11-19 | HERMAN JOAN E Director | Sold | $3.2m44.0k shares |
| 2025-11-06 | Geary Richard S EVP, Chief Development Officer | Sold plan | $2.5m33.0k shares |
| 2025-11-06 | Birchler Brian EVP, Corp and Development Ops | Sold plan | $609.4k8.0k shares |
| 2025-11-05 | Geary Richard S EVP, Chief Development Officer | Sold plan | $120.1k1.6k shares |
| 2025-11-03 | Geary Richard S EVP, Chief Development Officer | Sold plan | $126.1k1.7k shares |
| 2025-10-31 | LOSCALZO JOSEPH Director | Sold plan | $1.2m16.0k shares |
| 2025-10-31 | WENDER JOSEPH H Director · by Trust | Sold plan | $841.8k11.2k shares |
| 2025-10-30 | WENDER JOSEPH H Director · by Trust | Sold plan | $1.2m16.8k shares |
| 2025-10-16 | Devers Shannon L. EVP, Chief Human Resources Ofc | Sold plan | $93.0k1.3k shares |
| 2025-10-16 | Swayze Eric EVP Research · by Son | Sold | $3.9k53 shares |
| 2025-10-15 | Birchler Brian EVP, Corp and Development Ops | Sold plan | $897.5k12.4k shares |
| 2025-10-15 | Devers Shannon L. EVP, Chief Human Resources Ofc | Sold plan | $437.6k6.0k shares |
| 2025-10-15 | PARSHALL B LYNNE Director | Sold plan | $358.7k5.0k shares |
| 2025-10-14 | Birchler Brian EVP, Corp and Development Ops | Sold plan | $826.5k11.5k shares |
| 2025-10-06 | O'NEIL PATRICK R. EVP CLO & General Counsel | Sold plan | $937.4k13.4k shares |
| 2025-10-06 | Swayze Eric EVP Research | Sold plan | $472.7k6.8k shares |
| 2025-10-06 | Baroldi Joseph EVP, Chief Business Officer | Sold plan | $112.7k1.6k shares |
| 2025-10-06 | Monia Brett P Chief Executive Officer, director | Sold plan | $30.3k437 shares |
| 2025-10-02 | O'NEIL PATRICK R. EVP CLO & General Counsel | Sold plan | $4.4m64.7k shares |
| 2025-10-02 | Baroldi Joseph EVP, Chief Business Officer | Sold plan | $1.0m15.0k shares |
| 2025-10-02 | Swayze Eric EVP Research | Sold plan | $859.1k13.0k shares |
| 2025-10-01 | WENDER JOSEPH H Director · by Trust | Sold plan | $1.1m16.8k shares |
| 2025-10-01 | Swayze Eric EVP Research | Sold plan | $934.6k14.1k 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, Q4 2025
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.10% of their portfolio | 24.1m $1.9bn | Added +383.1k |
| Capital World Investors 0.19% of their portfolio | 18.0m $1.4bn | Added +5.2m |
| VANGUARD GROUP INC 0.02% of their portfolio | 16.4m $1.3bn | Reduced -41.3k |
| T. Rowe Price Investment Management, Inc. 0.47% of their portfolio | 14.9m $1.2bn | Added +1.7m |
| BlackRock, Inc. 0.01% of their portfolio | 10.6m $842.4m | Added +199.9k |
| WELLINGTON MANAGEMENT GROUP LLP 0.09% of their portfolio | 6.3m $495.3m | Reduced -328.5k |
| Bellevue Group AG 7.20% of their portfolio | 4.8m $379.9m | Reduced -1.4m |
| STATE STREET CORP 0.01% of their portfolio | 4.0m $314.5m | Reduced -413.8k |
| GEODE CAPITAL MANAGEMENT, LLC 0.02% of their portfolio | 3.1m $249.2m | Added +82.6k |
| TWO SIGMA ADVISERS, LP 0.47% of their portfolio | 3.1m $241.5m | Added +979.0k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.03% of their portfolio | 3.0m $236.4m | Added +258.2k |
| TWO SIGMA INVESTMENTS, LP 0.31% of their portfolio | 2.7m $210.3m | Added +1.1m |
| Tweedy, Browne Co LLC 15.74% of their portfolio | 2.5m $195.0m | Reduced -436.3k |
| JPMORGAN CHASE & CO 0.01% of their portfolio | 2.3m $182.3m | Added +1.2m |
| CITADEL ADVISORS LLC 0.11% of their portfolio | 2.1m $168.9m | Reduced -267.4k |
| DEERFIELD MANAGEMENT COMPANY, L.P. 2.01% of their portfolio | 2.0m $156.6m | Unchanged |
| BAKER BROS. ADVISORS LP 0.83% of their portfolio | 1.8m $141.8m | Added +1.2m |
| Deep Track Capital, LP 3.07% of their portfolio | 1.7m $134.5m | Reduced -2.1m |
| AMERICAN CENTURY COMPANIES INC 0.06% of their portfolio | 1.6m $127.9m | Added +244.9k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.02% of their portfolio | 1.5m $122.0m | Added +21.9k |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC 3.26% of their portfolio | 1.5m $115.7m | Added +712.7k |
| Pictet Asset Management Holding SA 0.11% of their portfolio | 1.4m $112.5m | Added +25.4k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.02% of their portfolio | 1.4m $109.8m | Added +234.4k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.12% of their portfolio | 1.4m $107.0m | Added +293.1k |
| Polar Capital Holdings Plc 0.48% of their portfolio | 1.3m $105.5m | Added +299.8k |
| FRANKLIN RESOURCES INC 0.03% of their portfolio | 1.3m $104.5m | Added +1.3m |
| Invesco Ltd. 0.01% of their portfolio | 1.3m $100.4m | Added +750.2k |
| Artisan Partners Limited Partnership 0.14% of their portfolio | 1.2m $93.5m | Added +291.3k |
| ROYAL BANK OF CANADA 0.02% of their portfolio | 1.1m $88.5m | Reduced -107.8k |
| Connor, Clark & Lunn Investment Management Ltd. 0.22% of their portfolio | 1.1m $85.2m | Added +198.2k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.05% of their portfolio | 1.1m $84.1m | Added +433.2k |
| UBS Group AG 0.02% of their portfolio | 1.0m $82.7m | Reduced -1.9k |
| MORGAN STANLEY 0.00% of their portfolio | 1.0m $80.7m | Reduced -160.4k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.10% of their portfolio | 864.9k $68.4m | First filing |
| GOLDMAN SACHS GROUP INC 0.01% of their portfolio | 856.0k $67.7m | Added +78.4k |
| NOMURA HOLDINGS INC 0.19% of their portfolio | 848.8k $67.1m | Added +115.4k |
| NORTHERN TRUST CORP 0.01% of their portfolio | 846.7k $67.0m | Added +1.8k |
| BARCLAYS PLC 0.03% of their portfolio | 842.9k $66.7m | Added +128.8k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.02% of their portfolio | 812.7k $64.3m | Reduced -49.8k |
| GW&K Investment Management, LLC 0.54% of their portfolio | 786.7k $62.2m | Added +522.7k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 783.6k $62.0m | Reduced -71.7k |
| TD Asset Management Inc 0.05% of their portfolio | 773.2k $61.2m | Reduced -187.1k |
| GROUPAMA ASSET MANAGMENT 0.89% of their portfolio | 766.9k $60.7m | Added +205.1k |
| Candriam S.C.A. 0.27% of their portfolio | 677.6k $53.6m | Added +66.4k |
| Nuveen, LLC 0.01% of their portfolio | 660.8k $52.3m | Added +245.2k |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 598.7k $47.4m | Reduced -167.1k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.16% of their portfolio | 585.0k $46.3m | Reduced -218.1k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.71% of their portfolio | 575.0k $45.5m | New |
| Tri Locum Partners LP 5.72% of their portfolio | 557.2k $44.1m | New |
| Eversept Partners, LP 2.39% of their portfolio | 538.2k $42.6m | Reduced -443 |
| Bank of New York Mellon Corp 0.01% of their portfolio | 537.9k $42.6m | Added +5.8k |
| FIRST TRUST ADVISORS LP 0.03% of their portfolio | 525.2k $41.6m | Added +450.0k |
| Alyeska Investment Group, L.P. 0.11% of their portfolio | 481.7k $38.1m | Added +170.5k |
| Hudson Bay Capital Management LP 0.22% of their portfolio | 475.0k $37.6m | Reduced -40.0k |
| PINNACLE ASSOCIATES LTD 0.47% of their portfolio | 462.0k $36.5m | Reduced -19.8k |
| Amundi 0.01% of their portfolio | 460.9k $36.5m | Added +359.4k |
| Squarepoint Ops LLC 0.07% of their portfolio | 436.3k $34.5m | Added +52.5k |
| Corient Private Wealth LP 0.02% of their portfolio | 431.4k $34.1m | Added +424.8k |
| ARK Investment Management LLC 0.22% of their portfolio | 423.0k $33.5m | Reduced -208.2k |
| TEACHER RETIREMENT SYSTEM OF TEXAS 0.12% of their portfolio | 422.9k $33.5m | Reduced -51.0k |
| BOONE CAPITAL MANAGEMENT LLC 10.37% of their portfolio | 417.8k $33.1m | Unchanged |
| C WorldWide Group Holding A/S 0.51% of their portfolio | 366.0k $29.0m | Reduced -60.0k |
| Jain Global LLC 0.28% of their portfolio | 356.3k $28.2m | Added +130.5k |
| ALLIANCEBERNSTEIN L.P. 0.01% of their portfolio | 341.8k $27.0m | Added +287.6k |
| BNP PARIBAS FINANCIAL MARKETS 0.02% of their portfolio | 334.6k $26.5m | Reduced -48.6k |
| D. E. Shaw & Co., Inc. 0.02% of their portfolio | 332.8k $26.3m | Reduced -298.1k |
| Legal & General Group Plc 0.01% of their portfolio | 325.1k $25.7m | Added +5.6k |
| NORGES BANK 0.00% of their portfolio | 320.2k $25.3m | Not comparable |
| Swiss National Bank 0.01% of their portfolio | 298.5k $23.6m | Added +5.4k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 280.0k $22.2m | Reduced -5.2k |
| Zurich Insurance Group Ltd/FI 0.14% of their portfolio | 261.8k $20.7m | New |
| RAYMOND JAMES FINANCIAL INC 0.01% of their portfolio | 257.2k $20.3m | Added +16.8k |
| MARSHALL WACE, LLP 0.02% of their portfolio | 256.9k $20.3m | Reduced -701.9k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.03% of their portfolio | 241.9k $19.1m | Added +73.6k |
| Privium Fund Management B.V. 3.51% of their portfolio | 240.8k $19.1m | Reduced -8.1k |
| Davern Capital Partners, LP 6.10% of their portfolio | 238.5k $18.9m | First filing |
| Orion Investment Co 5.43% of their portfolio | 225.2k $17.8m | Added +456 |
| RENAISSANCE TECHNOLOGIES LLC 0.03% of their portfolio | 223.6k $17.7m | Reduced -263.1k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.03% of their portfolio | 219.6k $17.4m | Added +22.1k |
| DAVENPORT & Co LLC 0.09% of their portfolio | 217.9k $17.2m | Added +155.3k |
| California Public Employees Retirement System 0.01% of their portfolio | 213.4k $16.9m | Reduced -2.5k |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.24% of their portfolio | 203.7k $16.1m | Added +10.7k |
| Ikarian Capital, LLC 2.07% of their portfolio | 202.0k $16.0m | Reduced -213.1k |
| STIFEL FINANCIAL CORP 0.01% of their portfolio | 198.9k $15.7m | Reduced -3.8k |
| SECTOR GAMMA AS 3.34% of their portfolio | 185.0k $14.6m | Reduced -86.0k |
| Focus Partners Wealth 0.02% of their portfolio | 181.8k $14.4m | New |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 176.0k $13.9m | Added +133.8k |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 175.4k $13.9m | Reduced -6.7k |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main 0.01% of their portfolio | 167.7k $13.3m | New |
| Man Group plc 0.03% of their portfolio | 166.0k $13.1m | Reduced -167.8k |
| Sicart Associates LLC 3.43% of their portfolio | 163.6k $12.9m | Reduced -761 |
| Rhenman & Partners Asset Management AB 1.17% of their portfolio | 158.5k $12.5m | Reduced -151.5k |
| CenterBook Partners LP 0.60% of their portfolio | 153.9k $12.2m | New |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.01% of their portfolio | 153.2k $12.1m | Added +55.2k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 149.4k $11.8m | Added +60.6k |
| GREAT LAKES ADVISORS, LLC 0.10% of their portfolio | 149.2k $11.8m | Reduced -37.8k |
| ADAR1 Capital Management, LLC 0.87% of their portfolio | 147.1k $11.6m | Added +13.3k |
| Artia Global Partners LP 1.84% of their portfolio | 144.4k $11.4m | Added +84.2k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 144.2k $11.4m | Reduced -939 |
| Fisher Asset Management, LLC 0.00% of their portfolio | 141.6k $11.2m | Added +135.4k |