Ionis Pharmaceuticals Inc
IONS- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0000874015
In the last 90 days, Ionis Pharmaceuticals Inc insiders filed 1 open-market purchase and 7 sales; 515 institutions reported holding it in 13F filings for Q2 2026, worth $14.3B in total; ARK Invest is the only superinvestor holding it.
Holders of 5% or more of IONS
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Ionis Pharmaceuticals Inc, largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Vanguard Group Inc | 13G/A | 10.43%16.5M shares | – | Jan 8, 20251 filing | Jan 8, 2025 | SEC |
| T. Rowe Price Investment Management, Inc. | 13G/A | 8.30%13.2M shares | −1.70 ppfrom 10.00% | Feb 7, 20252 filings | Nov 14, 2025 | SEC |
| Capital World Investors | 13G | 7.30%11.5M shares | New | Feb 13, 20251 filing | Feb 13, 2025 | SEC |
| BlackRock, Inc. | 13G/A | 5.70%9.07M shares | – | Apr 17, 20251 filing | Apr 17, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
6 Schedule 13D and 13G filings on Ionis Pharmaceuticals Inc, newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Nov 14, 202512:18 PM ET | T. Rowe Price Investment Management, Inc. | 13G/A | 8.30%13.2M shares | −1.70 ppfrom 10.00% | Sep 30, 2025 | SEC |
| Aug 12, 202510:34 AM ET | Wellington Management Group LLPand 2 others | 13G/A | 4.30%6.88M shares | –Below 5% | Jun 30, 2025 | SEC |
| Apr 17, 20259:35 AM ET | BlackRock, Inc. | 13G/A | 5.70%9.07M shares | – | Mar 31, 2025 | SEC |
| Feb 13, 20254:53 PM ET | Capital World Investors | 13G | 7.30%11.5M shares | New | Dec 31, 2024 | SEC |
| Feb 7, 202511:55 AM ET | T. Rowe Price Investment Management, Inc. | 13G/A | 10.00%15.9M shares | – | Jan 31, 2025 | SEC |
| Jan 8, 202511:29 AM ET | Vanguard Group Inc | 13G/A | 10.43%16.5M shares | – | Dec 31, 2024 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Ionis Pharmaceuticals Inc shares.
No Form 144 notices for Ionis Pharmaceuticals Inc are on file.