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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 Dec 2025
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 22 Jan 2026
Managers listing it
35
at least, of 95 tracked, among listed positions
Comparable managers
92
filed both Q3 2025 and Q4 2025; 17 listed it in both
Shares listed
67,438,108
combined, among listed positions
Reported value
$5.3bn
combined, at the quarter end

Among the 92 comparable managers: 15 buyers (opened or added shares) and 20 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was +4,838,240.

Managers listing IONS in Q4 2025

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q3 2025, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

35 of 35 holders

ActionFiling
Fidelity (FMR LLC)24,072,101$1.9bn0.10%Added+383,06317 Feb 2026 (the filing on sec.gov)
Capital World Investors17,961,299$1.4bn0.19%Added+5,238,57111 Feb 2026 (the filing on sec.gov)
Wellington Management Group LLP6,260,325$495m0.09%Trimmed-328,48617 Feb 2026 (the filing on sec.gov)
Two Sigma Advisers LP3,052,111$241m0.47%Added+979,00017 Feb 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc2,987,840$236munder 0.1%Added+258,15517 Feb 2026 (the filing on sec.gov)
Two Sigma Investments LP2,658,646$210m0.30%Added+1,082,70317 Feb 2026 (the filing on sec.gov)
Citadel Advisors LLC2,134,636$169munder 0.1%Trimmed-267,42917 Feb 2026 (the filing on sec.gov)
Invesco Ltd1,269,290$100munder 0.1%Added+750,22019 Feb 2026 (the filing on sec.gov)
Artisan Partners LP1,181,416$93m0.14%Added+291,34417 Feb 2026 (the filing on sec.gov)
Arrowstreet Capital LP1,063,327$84munder 0.1%Added+433,19113 Feb 2026 (the filing on sec.gov)
MFS Investment Management812,747$64munder 0.1%Trimmed-49,84622 Jan 2026 (the filing on sec.gov)
Voloridge Investment Management LLC584,970$46m0.16%Trimmed-218,07717 Feb 2026 (the filing on sec.gov)
Hudson Bay Capital Management LP475,000$38m0.12%Trimmed-40,00013 Feb 2026 (the filing on sec.gov)
Squarepoint Ops LLC436,279$35munder 0.1%Added+52,48713 Feb 2026 (the filing on sec.gov)
ARK Investment Management LLC422,968$33m0.22%Trimmed-208,24711 Feb 2026 (the filing on sec.gov)
AllianceBernstein LP341,849$27munder 0.1%Added+287,58717 Feb 2026 (the filing on sec.gov)
D. E. Shaw & Co.332,803$26munder 0.1%Trimmed-298,13517 Feb 2026 (the filing on sec.gov)
Marshall Wace LLP256,933$20munder 0.1%Trimmed-701,89613 Feb 2026 (the filing on sec.gov)
Renaissance Technologies LLC223,607$18munder 0.1%Trimmed-263,10712 Feb 2026 (the filing on sec.gov)
Man Group PLC166,042$13munder 0.1%Trimmed-167,77817 Feb 2026 (the filing on sec.gov)
Balyasny Asset Management LLC120,577$9.5munder 0.1%Trimmed-639,53417 Feb 2026 (the filing on sec.gov)
Neuberger Berman Group LLC108,044$8.5munder 0.1%Trimmed-6,69927 Oct 2026 (the filing on sec.gov)
Millennium Management LLC93,262$7.4munder 0.1%Trimmed-686,30817 Feb 2026 (the filing on sec.gov)
ExodusPoint Capital Management LP83,875$6.6m0.05%Trimmed-68,25017 Feb 2026 (the filing on sec.gov)
Janus Henderson Group Ltd68,191$5.4munder 0.1%Added+4,31417 Feb 2026 (the filing on sec.gov)
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Largest increases and reductions, by shares

Q3 2025 to Q4 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 (2)

Exited (2)

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 →