13F Insight
DOSSIER · 13F Holders · Q1 2026Inflation hedgeYield
ALNY 1 09/15/27

ALNYLAM PHARMACEUTICALS INC

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

CUSIP 02043QAB3·51 13F holders·last filed Mar 31, 2026
Market cap
—
▲ 7.0%
vs prior quarter
13F value held
$431M
69.0% inst. owned
of float
Holders
51
+73 QoQ
filers reporting
Activity
+74 / −14
+897 added · −892 reduced
this quarter
Concentration
17.89%
STEELHEAD PARTNERS LLC #1
top holder share
AI Holders Summary · Q1 2026

51 institutions reported ALNY 1 09/15/27 in Q1 2026. STEELHEAD PARTNERS LLC leads at 17.9% of the visible book. +73 net new institutions vs prior quarter — accumulation reading.

Top holders

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

#HolderValueShares% port.Quarter
01
STEELHEAD PARTNERS LLC
CIK 0001133521
$77M60.0M5.54%Q1 202602
BNP PARIBAS FINANCIAL MARKETS
CIK 0001166588
$41M32.3M0.02%Q1 202603
Boussard & Gavaudan Investment Management LLP
CIK 0001614986
$41M32K3.85%Q1 202604
Alberta Investment Management Corp
CIK 0001463559· Sovereign
$32M25.0M0.19%Q1 202605
DeepCurrents Investment Group LLC
CIK 0001754535
$31M24.0M0.99%Q1 202606
STATE STREET CORP
CIK 0000093751
$29M22.8M0.00%Q1 202607
CSS LLC/IL
CIK 0001103646
$24M18.6M1.14%Q1 202608
FMR LLC
CIK 0000315066
$24M18.4M0.00%Q1 202609
BlackRock, Inc.
CIK 0002012383
$21M16.6M0.00%Q1 202610
MACKAY SHIELDS LLC
CIK 0000061227
$19M14.8M0.70%Q1 202611
MANUFACTURERS LIFE INSURANCE COMPANY, THE
CIK 0000928047
$18M13.8M0.02%Q1 202612
BANK OF AMERICA CORP /DE/
CIK 0000070858
$14M10.9M0.00%Q1 202613
BNP Paribas Asset Management Holding S.A.
CIK 0001520354
$13M9.8M0.01%Q1 202614
Universal- Beteiligungs- und Servicegesellschaft mbH
CIK 0002057170
$11M8.2M0.02%Q1 202615
TWO SIGMA INVESTMENTS, LP
CIK 0001179392
$8M6.0M0.01%Q1 202616
CITIGROUP INC
CIK 0000831001
$7M5.7M0.00%Q1 202617
Warberg Asset Management LLC
CIK 0001597506
$6M5.0M1.07%Q1 202618
AXA Investment Managers S.A.
CIK 0001826635
$6M1.4M0.02%Q3 202519
SSI INVESTMENT MANAGEMENT LLC
CIK 0000938487
$5M4.1M0.36%Q1 202620
MORGAN STANLEY
CIK 0000895421
$4M3.1M0.00%Q1 2026
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