DOSSIER · 13F Holders · Q1 2026Healthcare · Pharmaceutical Preparations
IONS

IONIS PHARMACEUTICALS INC

514 institutions still hold IONIS PHARMACEUTICALS INC as of Q1 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 462222100·Pharmaceutical Preparations·514 13F holders·last filed Mar 31, 2026
Market cap
13F value held
$9.5B
visible holders
Holders
514
filers reporting
Concentration
19.47%
FMR LLC #1
top holder share
AI Holders Summary · Q1 2026

In contrast to Q1 2026 when domestic wealth manager Davenport & Co LLC single-handedly anchored institutional volume in Ionis Pharmaceuticals Inc (IONS), Q2 2026 witnessed a surge in broad international institutional buying. Swedbank AB executed the quarter's largest buy-side move, deploying $5.03 million in net inflows to expand its holding to $7.59 million (95,666 shares). Quantitative firm Y-Intercept (Hong Kong) Ltd established a new $5.34 million stake (67,374 shares), while Davenport & Co expanded its #1 position by adding $3.63 million in net flow to reach $22.51 million (283,960 shares, 35.37% of reported 13F capital). Across 71 tracked filers, total institutional value reached $63.66 million.

A concerted inflow from European, Asian, and US institutional managers defined Ionis Pharmaceuticals Inc's (IONS) Q2 2026 holdings, pushing total tracked 13F capital to $63.66 million across 71 reporting filers.

Institutional Buyer & Seller Breakdown

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

#HolderValueShares% port.Quarter
01
FMR LLC
CIK 0000315066
$1.8B24.6M0.10%Q1 2026
02
Capital World Investors
CIK 0001422849
$1.6B21.2M0.22%Q1 2026
03
BlackRock, Inc.
CIK 0002012383
$784M10.4M0.01%Q1 2026
04
Vanguard Portfolio Management
CIK 0002100121· Index
$586M7.8M0.03%Q1 2026
05
VANGUARD CAPITAL MANAGEMENT LLC
CIK 0002100119· Index
$535M7.1M0.01%Q1 2026
06
WELLINGTON MANAGEMENT GROUP LLP
CIK 0000902219
$480M6.4M0.09%Q1 2026
07
T. Rowe Price Investment Management, Inc.
CIK 0001897612
$462M6.2M0.32%Q1 2026
08
TWO SIGMA INVESTMENTS, LP
CIK 0001179392
$440M5.9M0.35%Q1 2026
09
Bellevue Group AG
CIK 0001674546
$380M4.8M7.20%Q4 2025
10
GEODE CAPITAL MANAGEMENT, LLC
CIK 0001214717· Index
$305M4.0M0.02%Q1 2026
11
STATE STREET CORP
CIK 0000093751
$300M4.0M0.01%Q1 2026
12
ROYAL BANK OF CANADA
CIK 0001000275
$285M3.8M0.05%Q1 2026
13
TWO SIGMA ADVISERS, LP
CIK 0001478735
$241M3.1M0.47%Q4 2025
14
PRICE T ROWE ASSOCIATES INC /MD/
CIK 0000080255
$227M3.0M0.03%Q1 2026
15
Tweedy, Browne Co LLC
CIK 0000732905
$195M2.5M15.74%Q4 2025
16
CITADEL ADVISORS LLC
CIK 0001423053
$183M2.3M0.03%Q4 2025
17
JPMORGAN CHASE & CO
CIK 0000019617
$171M2.4M0.01%Q1 2026
18
DEERFIELD MANAGEMENT COMPANY, L.P.
CIK 0001009258
$157M2.0M2.00%Q4 2025
19
Artisan Partners Limited Partnership
CIK 0001466153
$155M2.1M0.25%Q1 2026
20
Deep Track Capital, LP
CIK 0001856083
$146M1.9M2.39%Q1 2026
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Insiders at IONIS PHARMACEUTICALS INC
Berthelsen Spencer RHerman Joan EHantson LudwigReikes Peter NBennett C FrankDiaz Allene M.Kordasiewicz Holly B.Hayden Michael R