Who owns IONS (IONS)
Which tracked institutional funds hold IONS, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See IONS company fundamentals →
Ownership as of the 2026-Q1 13F filings. 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
121 tracked funds added or opened IONS while 137 trimmed or exited it between 2025-Q4 and 2026-Q1 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
IONS’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.1% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in IONS divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 494 tracked filers holding IONS, 253 increased or opened the position and 227 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in IONS between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 35
- VANGUARD PORTFOLIO MANAGEMENT LLC$586M
- VANGUARD CAPITAL MANAGEMENT LLC$535M
- VANGUARD FIDUCIARY TRUST CO$77M
- PERCEPTIVE ADVISORS LLC$38M
- Capital Research Global Investors$24M
- TimesSquare Capital Management, LLC$21M
Full exits 29
- VANGUARD GROUP INC$1.3B
- TWO SIGMA ADVISERS, LP$241M
- Tri Locum Partners LP$44M
- Balyasny Asset Management L.P.$10M
- Skandinaviska Enskilda Banken AB (publ)$9M
- HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND$9M
Largest adds
- TWO SIGMA INVESTMENTS, LP$230M
- ROYAL BANK OF CANADA$197M
- Capital World Investors$170M
- MILLENNIUM MANAGEMENT LLC$72M
- Artisan Partners Limited Partnership$61M
- GOLDMAN SACHS GROUP INC$60M
Largest trims
- Bellevue Group AG$243M
- BlackRock, Inc.$185M
- CITADEL ADVISORS LLC$98M
- FMR LLC$61M
- NOMURA HOLDINGS INC$54M
- BARCLAYS PLC$45M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 24,553,495 | $1.8B | 13.2% | 2026-Q1 |
| Capital World Investors added | 21,186,369 | $1.6B | 11.4% | 2026-Q1 |
| BlackRock, Inc. trimmed | 8,754,337 | $657M | 4.7% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 7,808,902 | $586M | 4.2% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 7,118,330 | $535M | 3.8% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP added | 6,383,542 | $479M | 3.4% | 2026-Q1 |
| T. Rowe Price Investment Management, Inc. added | 6,159,027 | $462M | 3.3% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 5,857,629 | $440M | 3.1% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 3,984,332 | $305M | 2.2% | 2026-Q1 |
| STATE STREET CORP added | 3,995,564 | $300M | 2.1% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 3,801,815 | $285M | 2.0% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 3,025,251 | $227M | 1.6% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 2,363,567 | $171M | 1.2% | 2026-Q1 |
| Tweedy, Browne Co LLC trimmed | 2,275,625 | $171M | 1.2% | 2026-Q1 |
| Artisan Partners Limited Partnership added | 2,058,308 | $155M | 1.1% | 2026-Q1 |
| BAKER BROS. ADVISORS LP added | 2,047,727 | $154M | 1.1% | 2026-Q1 |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 1,979,669 | $149M | 1.1% | 2026-Q1 |
| Deep Track Capital, LP added | 1,950,000 | $146M | 1.0% | 2026-Q1 |
| Bellevue Group AG trimmed | 1,818,665 | $137M | 1.0% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 1,699,847 | $128M | 0.9% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 1,663,803 | $125M | 0.9% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 1,583,266 | $119M | 0.9% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 1,575,023 | $118M | 0.8% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 1,475,632 | $111M | 0.8% | 2026-Q1 |
| Pictet Asset Management Holding SA added | 1,434,995 | $107M | 0.8% | 2026-Q1 |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC trimmed | 1,404,033 | $105M | 0.8% | 2026-Q1 |
| Invesco Ltd. trimmed | 1,169,890 | $88M | 0.6% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 1,051,506 | $79M | 0.6% | 2026-Q1 |
| MORGAN STANLEY added | 1,026,509 | $77M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 1,024,377 | $77M | 0.6% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 942,534 | $71M | 0.5% | 2026-Q1 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. trimmed | 907,533 | $68M | 0.5% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 874,089 | $66M | 0.5% | 2026-Q1 |
| NORTHERN TRUST CORP added | 868,179 | $65M | 0.5% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 840,598 | $63M | 0.5% | 2026-Q1 |
| Polar Capital Holdings Plc trimmed | 829,511 | $62M | 0.4% | 2026-Q1 |
| GROUPAMA ASSET MANAGMENT added | 824,540 | $62M | 0.4% | 2026-Q1 |
| UBS Group AG trimmed | 808,443 | $61M | 0.4% | 2026-Q1 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. trimmed | 785,281 | $59M | 0.4% | 2026-Q1 |
| GW&K Investment Management, LLC trimmed | 779,349 | $59M | 0.4% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 737,859 | $55M | 0.4% | 2026-Q1 |
| Squarepoint Ops LLC added | 695,276 | $52M | 0.4% | 2026-Q1 |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC added | 672,858 | $51M | 0.4% | 2026-Q1 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ trimmed | 666,116 | $50M | 0.4% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 660,144 | $50M | 0.4% | 2026-Q1 |
| Nuveen, LLC trimmed | 648,496 | $49M | 0.3% | 2026-Q1 |
| Eversept Partners, LP added | 632,100 | $47M | 0.3% | 2026-Q1 |
| EVENTIDE ASSET MANAGEMENT, LLC | 575,000 | $43M | 0.3% | 2026-Q1 |
| TD Asset Management Inc trimmed | 529,954 | $40M | 0.3% | 2026-Q1 |
| TEACHER RETIREMENT SYSTEM OF TEXAS added | 523,932 | $39M | 0.3% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 514,617 | $39M | 0.3% | 2026-Q1 |
| PERCEPTIVE ADVISORS LLC new | 504,000 | $38M | 0.3% | 2026-Q1 |
| BOONE CAPITAL MANAGEMENT LLC added | 500,522 | $38M | 0.3% | 2026-Q1 |
| Candriam S.C.A. trimmed | 484,053 | $36M | 0.3% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 479,460 | $36M | 0.3% | 2026-Q1 |
| Alyeska Investment Group, L.P. trimmed | 473,150 | $36M | 0.3% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 468,363 | $35M | 0.3% | 2026-Q1 |
| NEUBERGER BERMAN GROUP LLC added | 443,272 | $33M | 0.2% | 2026-Q1 |
| PINNACLE ASSOCIATES LTD trimmed | 436,457 | $33M | 0.2% | 2026-Q1 |
| D. E. Shaw & Co., Inc. added | 429,599 | $32M | 0.2% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 400,669 | $32M | 0.2% | 2026-Q1 |
| Davern Capital Partners, LP added | 386,903 | $29M | 0.2% | 2026-Q1 |
| C WorldWide Group Holding A/S | 366,000 | $27M | 0.2% | 2026-Q1 |
| NEW YORK STATE COMMON RETIREMENT FUND added | 350,414 | $26M | 0.2% | 2026-Q1 |
| NORGES BANK added | 858,228 | $26M | 0.2% | 2026-Q1 |
| Capital Research Global Investors new | 323,015 | $24M | 0.2% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 305,549 | $23M | 0.2% | 2026-Q1 |
| Swiss National Bank added | 304,500 | $23M | 0.2% | 2026-Q1 |
| Hudson Bay Capital Management LP trimmed | 295,100 | $22M | 0.2% | 2026-Q1 |
| Legal & General Group Plc trimmed | 294,679 | $22M | 0.2% | 2026-Q1 |
| Privium Fund Management B.V. added | 290,024 | $22M | 0.2% | 2026-Q1 |
| BARCLAYS PLC trimmed | 289,874 | $22M | 0.2% | 2026-Q1 |
| ARK Investment Management LLC trimmed | 288,716 | $22M | 0.2% | 2026-Q1 |
| TimesSquare Capital Management, LLC new | 275,674 | $21M | 0.1% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 267,215 | $20M | 0.1% | 2026-Q1 |
| California Public Employees Retirement System added | 255,485 | $19M | 0.1% | 2026-Q1 |
| HRT FINANCIAL LP added | 252,250 | $19M | 0.1% | 2026-Q1 |
| Zurich Insurance Group Ltd/FI trimmed | 239,645 | $18M | 0.1% | 2026-Q1 |
| DAVENPORT & Co LLC added | 238,238 | $18M | 0.1% | 2026-Q1 |
| J. Goldman & Co LP added | 235,260 | $18M | 0.1% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC trimmed | 235,121 | $18M | 0.1% | 2026-Q1 |
| ExodusPoint Capital Management, LP added | 227,084 | $17M | 0.1% | 2026-Q1 |
| Orion Investment Co trimmed | 225,015 | $17M | 0.1% | 2026-Q1 |
| Universal- Beteiligungs- und Servicegesellschaft mbH added | 219,652 | $16M | 0.1% | 2026-Q1 |
| TOCQUEVILLE ASSET MANAGEMENT L.P. added | 219,220 | $16M | 0.1% | 2026-Q1 |
| Handelsbanken Fonder AB added | 213,911 | $16M | 0.1% | 2026-Q1 |
| Trexquant Investment LP added | 213,645 | $16M | 0.1% | 2026-Q1 |
| Jump Financial, LLC added | 206,675 | $16M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 16,200,527 | $1.3B | 9.2% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 3,052,111 | $241M | 1.7% | 2025-Q4 stale |
| ORBIMED ADVISORS LLC trimmed | 2,540,136 | $77M | 0.5% | 2025-Q1 stale |
| BVF INC/IL | 1,913,385 | $76M | 0.5% | 2025-Q2 stale |
| MACQUARIE GROUP LTD trimmed | 1,131,936 | $74M | 0.5% | 2025-Q3 stale |
| Vestal Point Capital, LP added | 1,075,000 | $70M | 0.5% | 2025-Q3 stale |
| Tri Locum Partners LP new | 557,174 | $44M | 0.3% | 2025-Q4 stale |
| TANG CAPITAL MANAGEMENT LLC added | 550,000 | $36M | 0.3% | 2025-Q3 stale |
| Woodline Partners LP added | 732,813 | $29M | 0.2% | 2025-Q2 stale |
| AXA Investment Managers S.A. new | 406,451 | $27M | 0.2% | 2025-Q3 stale |
| AXA S.A. added | 566,883 | $22M | 0.2% | 2025-Q2 stale |
| Camber Capital Management LP added | 725,000 | $22M | 0.2% | 2025-Q1 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.