Ionis Pharmaceuticals
IONS · NASDAQ
$45.40+$1.02 (+2.30%)TodayMarket closed ·
Prev close $44.38
Who owns IONS
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 57.9% of IONS’s shares.
- Fidelity Management & Research Company LLC14.8%
- Capital World Investors13.0%
- BlackRock Institutional Trust Company, N.A.5.4%
- Vanguard Portfolio Management, LLC4.7%
- Next 6 largest institutions19.9%
- All other shareholders42.1%
| Holder | Shares | % of shares |
|---|---|---|
| Fidelity Management & Research Company LLC | 24.63M | 14.82% |
| Capital World Investors | 21.67M | 13.04% |
| BlackRock Institutional Trust Company, N.A. | 9.05M | 5.45% |
| Vanguard Portfolio Management, LLC | 7.86M | 4.73% |
| Wellington Management Company, LLP | 7.65M | 4.60% |
| Vanguard Capital Management, LLC | 7.21M | 4.34% |
| Two Sigma Investments, LP | 6.25M | 3.76% |
| State Street Investment Management (US) | 4.33M | 2.61% |
| T. Rowe Price Investment Management, Inc. | 3.96M | 2.38% |
| Geode Capital Management, L.L.C. | 3.58M | 2.16% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| Fidelity Growth Company Fund | 8.50M | 5.12% |
| BB Biotech Fd | 7.85M | 4.72% |
| American Funds Growth Fund of America | 7.67M | 4.61% |
| American Funds SMALLCAP World Fund | 5.26M | 3.17% |
| Vanguard Total Stock Market Index Fund | 5.01M | 3.01% |
Insider trades
Form 4 filings by officers, directors and large holders
Over the last 6 months, insiders bought $1.06M (2 trades) and sold $23.89M (21 trades) of IONS on the open market.
| Insider | Type | Shares | Value |
|---|---|---|---|
| Birchler Brian | Other | 58 | $2.98K |
| O'NEIL PATRICK R. | Other | 63 | $3.23K |
| Monia Brett P | Other | 98 | $5.03K |
| BENNETT C FRANK | Other | 110 | $5.64K |
| Hayden Michael R | Buy | 5.00K | $258.00K |
| Hayden Michael R | Buy | 15.00K | $800.70K |
| Reikes Peter N | Award | 3.40K | — |
| HANTSON LUDWIG | Award | 3.40K | — |
| HERMAN JOAN E | Option exercise | 5.22K | — |
| HERMAN JOAN E | Option exercise | 5.22K | — |
Short interest
Settled Sep 30, 2026
- Shares short
- 22.51M
- Days to cover
- 4.61
- % of shares outstanding
- 13.54%
- Average daily volume
- 4.88M
- Change since last report
- +7.7%
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