| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| Capital World Investors | 11% | +54% | $1,420,920,160 | +$513,890,191 | 17,961,299 | +57% | Capital World Investors | 31 Dec 2025 |
| VANGUARD GROUP INC | 10% | $489,893,310 | 16,472,539 | The Vanguard Group | 31 Dec 2024 | |||
| T. Rowe Price Investment Management, Inc. | 8.3% | -17% | $860,738,398 | -$176,290,480 | 13,157,114 | -17% | T. Rowe Price Investment Management, Inc. | 30 Sep 2025 |
| BlackRock, Inc. | 5.7% | $269,638,216 | 9,066,517 | BlackRock, Inc. | 31 Mar 2025 | |||
| WELLINGTON MANAGEMENT GROUP LLP | 4.3% | $284,413,950 | 6,879,873 | Wellington Management Group LLP | 30 Jun 2025 |
As of 30 Sep 2025, 431 institutional investors reported holding 168,163,057 shares of IONIS PHARMACEUTICALS INC - Common Stock (IONS). This represents 104% of the company’s total 161,813,505 outstanding shares.
The largest institutional shareholders of IONIS PHARMACEUTICALS INC - Common Stock (IONS) together control 78% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| FMR LLC | 15% | 23,689,038 | +0.19% | 0.08% | $1,549,736,866 |
| VANGUARD GROUP INC | 10% | 16,481,730 | -1.4% | 0.02% | $1,078,234,776 |
| T. Rowe Price Investment Management, Inc. | 8.1% | 13,156,929 | -18% | 0.53% | $860,727,000 |
| Capital World Investors | 7.9% | 12,722,728 | +1.5% | 0.11% | $832,320,866 |
| BlackRock, Inc. | 6.5% | 10,447,940 | -4.1% | 0.01% | $683,504,235 |
| WELLINGTON MANAGEMENT GROUP LLP | 4.1% | 6,588,811 | +3.8% | 0.08% | $431,040,015 |
| Bellevue Group AG | 3.9% | 6,244,451 | -20% | 8.5% | $408,511,984 |
| STATE STREET CORP | 2.7% | 4,388,651 | -3.1% | 0.01% | $287,105,548 |
| Deep Track Capital, LP | 2.4% | 3,808,144 | -22% | 7% | $249,128,780 |
| GEODE CAPITAL MANAGEMENT, LLC | 1.9% | 3,066,289 | +6.1% | 0.01% | $200,632,333 |
| Tweedy, Browne Co LLC | 1.8% | 2,901,216 | +0.32% | 16% | $189,797,551 |
| PRICE T ROWE ASSOCIATES INC /MD/ | 1.7% | 2,729,685 | -13% | 0.02% | $178,577,000 |
| CITADEL ADVISORS LLC | 1.5% | 2,402,065 | +61% | 0.13% | $157,143,093 |
| TWO SIGMA ADVISERS, LP | 1.3% | 2,073,111 | -22% | 0.27% | $135,622,922 |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 1.2% | 1,979,669 | 2% | $129,509,946 | |
| TWO SIGMA INVESTMENTS, LP | 0.97% | 1,575,943 | -12% | 0.16% | $103,098,191 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 0.94% | 1,519,951 | +2.2% | 0.02% | $99,435,194 |
| Pictet Asset Management Holding SA | 0.86% | 1,393,124 | +129% | 0.09% | $90,476,958 |
| AMERICAN CENTURY COMPANIES INC | 0.85% | 1,372,225 | +190% | 0.05% | $89,771,090 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 0.81% | 1,315,000 | -65% | 0.14% | $86,027,300 |
| ROYAL BANK OF CANADA | 0.76% | 1,226,624 | +53% | 0.01% | $80,244,000 |
| MORGAN STANLEY | 0.73% | 1,180,316 | -13% | 0% | $77,216,430 |
| UBS AM, A DISTINCT BUSINESS UNIT OF UBS ASSET MANAGEMENT AMERICAS LLC | 0.71% | 1,154,166 | +46% | 0.02% | $75,505,539 |
| MACQUARIE GROUP LTD | 0.7% | 1,131,936 | -21% | 0.09% | $74,051,000 |
| Vestal Point Capital, LP | 0.66% | 1,075,000 | +115% | 3.2% | $70,326,500 |
| Period | Reported Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2025 Q4 | 25,830,741 | $2,040,642,641 | -$65,425,616 | $79.11 | 164 |
| 2025 Q3 | 168,163,057 | $11,001,576,890 | +$32,289,750 | $65.42 | 431 |
| 2025 Q2 | 168,850,675 | $6,672,661,270 | +$162,663,034 | $39.51 | 360 |
| 2025 Q1 | 165,860,888 | $5,004,903,523 | +$131,542,151 | $30.17 | 340 |
| 2024 Q4 | 160,366,928 | $5,606,135,985 | +$73,787,817 | $34.96 | 348 |
| 2024 Q3 | 157,127,745 | $6,297,681,566 | +$509,606,602 | $40.06 | 348 |
| 2024 Q2 | 143,207,231 | $6,823,555,846 | +$50,229,849 | $47.66 | 353 |
| 2024 Q1 | 141,857,166 | $6,150,040,836 | -$14,832,123 | $43.35 | 355 |
| 2023 Q4 | 142,480,404 | $7,209,128,718 | +$87,362,106 | $50.59 | 360 |
| 2023 Q3 | 139,863,021 | $6,344,228,254 | +$143,056,679 | $45.36 | 307 |
| 2023 Q2 | 136,544,584 | $5,601,663,585 | +$217,908,412 | $41.03 | 299 |
| 2023 Q1 | 131,377,079 | $4,693,255,222 | +$26,766,918 | $35.74 | 307 |
| 2022 Q4 | 130,693,455 | $4,936,957,475 | +$160,016,480 | $37.77 | 333 |
| 2022 Q3 | 126,410,568 | $5,587,594,025 | -$405,286,321 | $44.23 | 335 |
| 2022 Q2 | 124,531,298 | $4,607,099,903 | +$7,650,768 | $37.02 | 329 |
| 2022 Q1 | 124,797,488 | $4,621,087,277 | +$93,759,462 | $37.04 | 314 |
| 2021 Q4 | 123,208,578 | $3,749,220,496 | +$12,496,745 | $30.43 | 321 |
| 2021 Q3 | 121,685,400 | $4,081,694,378 | -$99,758,435 | $33.54 | 306 |
| 2021 Q2 | 124,355,726 | $4,958,884,573 | +$71,970,644 | $39.89 | 321 |
| 2021 Q1 | 123,194,653 | $5,537,925,756 | +$78,758,790 | $44.96 | 347 |
| 2020 Q4 | 120,098,693 | $6,792,775,467 | +$105,597,041 | $56.54 | 366 |
| 2020 Q3 | 118,507,239 | $5,623,405,509 | -$83,647,855 | $47.45 | 353 |
| 2020 Q2 | 120,124,891 | $7,083,094,879 | +$118,732,834 | $58.96 | 364 |
| 2020 Q1 | 117,978,069 | $5,578,869,902 | -$142,310,895 | $47.28 | 346 |
| 2019 Q4 | 120,722,063 | $7,295,059,529 | -$83,490,703 | $60.41 | 378 |
| 2019 Q3 | 121,924,630 | $7,301,296,355 | -$290,321,454 | $59.91 | 359 |
| 2019 Q2 | 126,579,263 | $8,133,847,761 | +$1,221,346,949 | $64.27 | 384 |
| 2019 Q1 | 117,270,258 | $9,518,406,006 | -$556,394 | $81.17 | 381 |
| 2018 Q4 | 117,697,799 | $6,364,862,646 | -$40,799,223 | $54.06 | 313 |
| 2018 Q3 | 118,360,713 | $6,104,227,241 | +$13,101,484 | $51.58 | 309 |
| 2018 Q2 | 118,306,675 | $4,930,015,291 | +$129,863,863 | $41.67 | 298 |
| 2018 Q1 | 115,119,301 | $5,074,956,068 | +$57,031,375 | $44.08 | 316 |
| 2017 Q4 | 113,771,923 | $5,722,698,300 | -$67,824,507 | $50.30 | 308 |
| 2017 Q3 | 115,132,406 | $5,837,399,453 | +$171,193,601 | $50.70 | 295 |
| 2017 Q2 | 111,706,831 | $5,682,739,525 | +$50,501,017 | $50.87 | 286 |
| 2017 Q1 | 110,927,384 | $4,459,598,265 | +$334,047,481 | $40.20 | 265 |
| 2016 Q4 | 108,655,474 | $5,196,935,022 | +$129,577,426 | $47.83 | 300 |
| 2016 Q3 | 106,327,670 | $3,894,299,306 | -$66,997,326 | $36.64 | 268 |
| 2016 Q2 | 109,204,497 | $2,543,222,575 | +$41,550,933 | $23.29 | 270 |
| 2016 Q1 | 105,183,376 | $4,259,436,314 | +$20,920,018 | $40.50 | 305 |
| 2015 Q4 | 103,265,462 | $6,394,592,642 | +$6,388,115,622 | $61.93 | 328 |