Security Snapshot

IONIS PHARMACEUTICALS INC - Common Stock (IONS) Institutional Ownership

CUSIP: 462222100

13F Institutional Holders and Ownership History from Q4 2015 to Q1 2026

Latest Period

Q4 2025

Institutions Reporting

487

Shares (Excl. Options)

170,216,462

Price

$79.11

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Type / Class
Equity / Common Stock
Symbol
IONS on Nasdaq
Shares outstanding
162,643,196
Price per share
$75.09
All holders as of 31 Dec 2025
Q4 2025
Total 13F shares
170,216,462
Total reported value
$13,463,110,852
% of total 13F portfolios
0.01%
Share change
+1,474,853
Value change
+$164,540,659
Number of holders
487
Price from insider filings
$75.09
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Quick Takeaways

  • IONS - IONIS PHARMACEUTICALS INC - Common Stock is tracked under CUSIP 462222100.
  • 487 institutions reported positions in Q4 2025.
  • 4 significant owners is listed from Schedule 13D/13G reporting.

What Changed

  • Holder count moved from 487 to 54 between Q4 2025 and Q1 2026.
  • Reported value moved from $13,463,110,852 to $195,992,016.

Why This Matters

  • You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
  • 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.

Source Evidence

Source: SEC Form 13F

Latest holder context comes from 487 institutions filings for Q4 2025.

Open SEC Evidence

Investment Quick Answers

What is CUSIP 462222100?
CUSIP 462222100 identifies IONS - IONIS PHARMACEUTICALS INC - Common Stock in SEC 13F datasets.

Where can I see the latest institutional holders?
Review the Q4 2025 holders report and the ownership history table below.

Significant Owners of IONIS PHARMACEUTICALS INC - Common Stock (IONS) based on Schedule 13D/G filings

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
T. Rowe Price Investment Management, Inc. 5.6% -34% $723,905,350 -$321,822,071 9,108,019 -31% T. Rowe Price Investment Management, Inc. 31 Dec 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 31 Dec 2025, 487 institutional investors reported holding 170,216,462 shares of IONIS PHARMACEUTICALS INC - Common Stock (IONS). This represents 105% of the company’s total 162,643,196 outstanding shares.

Top 25 Institutional Shareholders

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% 24,072,101 +1.6% 0.1% $1,904,343,910
Capital World Investors 11% 17,961,299 +41% 0.19% $1,420,918,364
VANGUARD GROUP INC 10% 16,440,459 -0.25% 0.02% $1,300,604,712
BlackRock, Inc. 6.5% 10,647,863 +1.9% 0.01% $842,352,443
T. Rowe Price Investment Management, Inc. 5.6% 9,108,019 -31% 0.45% $720,536,000
WELLINGTON MANAGEMENT GROUP LLP 3.8% 6,260,325 -5% 0.09% $495,254,312
Bellevue Group AG 3% 4,802,199 -23% 7.2% $379,901,963
STATE STREET CORP 2.4% 3,974,865 -9.4% 0.01% $314,451,570
GEODE CAPITAL MANAGEMENT, LLC 1.9% 3,148,849 +2.7% 0.02% $249,157,703
TWO SIGMA ADVISERS, LP 1.9% 3,052,111 +47% 0.47% $241,452,501
PRICE T ROWE ASSOCIATES INC /MD/ 1.8% 2,987,840 +9.5% 0.03% $236,370,000
TWO SIGMA INVESTMENTS, LP 1.6% 2,658,646 +69% 0.31% $210,325,485
Tweedy, Browne Co LLC 1.5% 2,464,930 -15% 16% $195,000,612
JPMORGAN CHASE & CO 1.4% 2,304,792 +323% 0.01% $182,332,112
CITADEL ADVISORS LLC 1.3% 2,134,636 -11% 0.11% $168,871,054
DEERFIELD MANAGEMENT COMPANY, L.P. 1.2% 1,979,669 0% 2% $156,611,615
BAKER BROS. ADVISORS LP 1.1% 1,791,841 +216% 0.83% $141,752,542
Deep Track Capital, LP 1% 1,700,000 -55% 3.1% $134,487,000
AMERICAN CENTURY COMPANIES INC 0.99% 1,617,106 +18% 0.06% $127,929,439
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.95% 1,541,841 +1.4% 0.02% $121,975,042
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC 0.9% 1,462,706 +95% 3.3% $115,714,672
Pictet Asset Management Holding SA 0.87% 1,418,491 +1.8% 0.11% $112,476,314
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.85% 1,388,567 +20% 0.02% $109,849,535
BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.83% 1,352,837 +28% 0.12% $107,029,000
Polar Capital Holdings Plc 0.82% 1,333,424 +29% 0.48% $105,487,173

Institutional Holders of IONIS PHARMACEUTICALS INC - Common Stock (IONS) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2026 Q1 2,618,898 $195,992,016 -$315,790 $75.09 54
2025 Q4 170,216,462 $13,463,110,852 +$164,540,659 $79.11 487
2025 Q3 168,163,078 $11,001,578,263 +$32,287,787 $65.42 433
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