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IONS in the 13F filings

Ionis Pharmaceuticals Inc · CUSIP 462222100

Sector · Pharmaceuticals and biotechnologyTheme · Healthcare: biopharma and medtech· L3VLUP-definedTheme · Pharmaceutical preparations
Quarter
Q3 2026 · early filersQ2 2026Q1 2026Q4 2025Q3 2025Q2 2025Q1 2025Q4 2024Q3 2024Q2 2024Q1 2024Q4 2023
Quarter end
31 Mar 2025
the date the book describes
Filed
5 Nov 2026
latest of these filings; the earliest 7 May 2025
Managers listing it
10
at least, of 95 tracked, among listed positions
Comparable managers
95
filed both Q4 2024 and Q1 2025; 10 listed it in both
Shares listed
51,079,884
combined, among listed positions
Reported value
$1.5bn
combined, at the quarter end

Among the 95 comparable managers: 7 buyers (opened or added shares) and 3 sellers (trimmed or exited), at least, among listed positions. Their net change in shares is not known from listed positions, because at least one of them lists it in only one of the two quarters.

Managers listing IONS in Q1 2025

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q4 2024, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

10 of 10 holders

ActionFiling
Fidelity (FMR LLC)23,613,585$712munder 0.1%Added+924,0945 Nov 2026 (the filing on sec.gov)
Capital World Investors12,361,994$373m0.06%Added+896,58112 May 2025 (the filing on sec.gov)
Wellington Management Group LLP8,416,421$254munder 0.1%Trimmed-255,72713 May 2025 (the filing on sec.gov)
Two Sigma Advisers LP2,092,011$63m0.14%Added+742,80015 May 2025 (the filing on sec.gov)
Two Sigma Investments LP1,685,853$51m0.11%Added+764,41415 May 2025 (the filing on sec.gov)
Hudson Bay Capital Management LP1,049,900$32m0.10%Added+228,70014 May 2025 (the filing on sec.gov)
ARK Investment Management LLC1,000,527$30m0.30%Trimmed-24,7337 May 2025 (the filing on sec.gov)
Schonfeld Strategic Advisors LLC560,359$17m0.10%Added+188,97815 May 2025 (the filing on sec.gov)
Artisan Partners LP203,178$6.1munder 0.1%Trimmed-49,45714 May 2025 (the filing on sec.gov)
PDT Partners LLC96,056$2.9m0.21%Added+67,06215 May 2025 (the filing on sec.gov)

Largest increases and reductions, by shares

Q4 2024 to Q1 2025, among managers that listed it in both quarters or opened it.

Increases

Reductions

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

New (0)

No new position among listed positions.

Exited (0)

No exit shown by a manager’s own filing.

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
16 in Q3 2024 to 13 in Q2 2026

Tracked managers listing it, at least.

0510152020162017201820192020202120222023202420252026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
IONS by quarter
QuarterHoldersReported valueBuyersSellers
Q4 201514$1.8bnn.a.n.a.
Q1 20167$1.1bnn.a.n.a.
Q2 20163$667mn.a.n.a.
Q3 20164$1.1bnn.a.n.a.
Q4 20167$1.6bnn.a.n.a.
Q1 20175$1.4bnn.a.n.a.
Q2 20176$1.9bnn.a.n.a.
Q3 20176$1.9bnn.a.n.a.
Q4 20177$1.9bnn.a.n.a.
Q1 20187$1.6bnn.a.n.a.
Q2 20186$1.6bnn.a.n.a.
Q3 20188$2.1bnn.a.n.a.
Q4 201811$2.1bnn.a.n.a.
Q1 201914$3.5bnn.a.n.a.
Q2 201911$2.8bnn.a.n.a.
Q3 201910$2.6bnn.a.n.a.
Q4 201910$2.5bnn.a.n.a.
Q1 202014$2.1bnn.a.n.a.
Q2 202012$2.6bnn.a.n.a.
Q3 202015$2.1bnn.a.n.a.
Q4 202014$2.5bnn.a.n.a.
Q1 20219$1.9bnn.a.n.a.
Q2 202110$1.8bnn.a.n.a.
Q3 20218$1.4bnn.a.n.a.
Q4 20219$1.3bnn.a.n.a.
Q1 20229$1.6bnn.a.n.a.
Q2 202212$1.6bnn.a.n.a.
Q3 202211$1.5bnn.a.n.a.
Q4 20229$1.2bnn.a.n.a.
Q1 20237$1.0bnn.a.n.a.
Q2 202310$1.3bnn.a.n.a.
Q3 202312$1.4bnn.a.n.a.
Q4 202314$1.9bn104
Q1 202415$1.7bn95
Q2 202417$2.1bn125
Q3 202416$2.1bn117
Q4 202411$1.7bn75
Q1 202510$1.5bn73
Q2 202513$2.1bn85
Q3 202518$3.6bn98
Q4 202515$4.9bn1520
Q1 202616$5.0bn2113
Q2 202613$5.5bn1319

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

IONS and LLY →IONS and JNJ →IONS and VRTX →Choose a stock to compare with IONS →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own IONS, latest filings →Back to the 13F Explorer →