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IONS · Ionis Pharmaceuticals Inc

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$54.25 -3.88 (-6.67%)
Market Cap
$9.65B
Shares
166.18M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 520
Total Value: $14,829,484,517
Total Shares: 187,028,438
Showing 1–100 of 552 holdings by value · page 1 of 6

Institutional Ownership Trend

26 quarters

Holder Concentration

Across 520 13F filers · Δ vs Mar 31, 2026
Top Holder
13.2%
Sep 2023 → Jun 2026 · range 13.2% – 15.3%
−0.8 pts
Top 5
38.8%
Sep 2023 → Jun 2026 · range 38.8% – 48.0%
−1.7 pts
Top 10
53.7%
Sep 2023 → Jun 2026 · range 53.7% – 65.2%
−1.7 pts
HHI
454
Sep 2023 → Jun 2026 · range 454 – 588
Broadly held−36

Quarterly Activity

vs Mar 31, 2026
New
67
Increased
209
Decreased
158
Sold Out
47
Unchanged
86
Holder count: +20
Institutional value: +12.3%
Shares held: +6.3%

Top Buyers

vs Mar 31, 2026
Institution Added Now Holds Open

Top Sellers

vs Mar 31, 2026
Institution Sold Now Holds Open

Top New Positions

vs Mar 31, 2026
Institution Acquired Value (USD) Open

Top Sold-Out Positions

vs Mar 31, 2026
Institution Previously Held Last Value (USD) Open
Showing 100 of 552
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Holder Value (USD) % of 13F Shares Open
Key facts CIK 874015 CUSIP 462222100 13F (30d) 369 filings 367 filers Visit website Investor relations