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ALNY · Alnylam Pharmaceuticals, Inc. · Holdings

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$233.29 +1.46 (+0.63%) At close · Oct 19
Market Cap
$31.34B
Shares
133.81M
Volume · Oct 19 1.35M Avg daily vol (3M) 1.72M

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.

Some SEC filings for this period have not finished importing. Holder totals and changes may be incomplete; these filings remain queued for recovery.
The Sep 30, 2026 filing window is still open — showing the latest known positions. Funds that have not filed yet carry their prior-quarter positions; a fund that filed without this stock counts as sold out. Each fund's Change is measured against its own previous reported quarter, shown in the Reported column. Pick a completed quarter in the Quarter selector below to put every fund on one quarter and see the stock-wide activity breakdown.
Holders: 798
Total Value: $40,690,402,761
Total Shares: 135,258,067
Showing 1–100 of 829 holdings by value · page 1 of 9

Institutional Ownership Trend

27 quarters

Holder Concentration

Across 800 13F filers
Top Holder
11.1%
Sep 2023 → Jun 2026 · range 10.7% – 13.8%
of institutional value
Top 5
39.4%
Sep 2023 → Jun 2026 · range 39.2% – 48.2%
of institutional value
Top 10
55.4%
Sep 2023 → Jun 2026 · range 55.4% – 64.1%
of institutional value
HHI
419
Sep 2023 → Jun 2026 · range 419 – 572
Broadly held

Who Holds ALNY

Last 8 quarters through Sep 30, 2026 (filing window open)

Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.

Jun 30, 2026, the newest closed quarter: 794 filers, like-for-like change +0.8%; actively managed books +0.1%; index-like books +3.5%.

Holder type Share Filers Change
Registered adviser 25.5% 402 +1.8%
Exempt adviser 1.0% 12 -39.0%
Adviser 26.5% 19 +8.8%
Bank 8.5% 33 -22.4%
Insurer 0.1% 4 +1.9%
Broker-dealer 0.0% 2 -21.2%
Registered fund 0.0% 1 +46.9%
Benefit plan 0.1% 5 -4.4%
Non-US 2.2% 7 +6.7%
Unknown 36.1% 309 +3.5%

The Sep 30, 2026 filing window is still open, so its bar carries the Jun 30, 2026 positions of filers that have not filed yet.

How the mix is measured

Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type, client base and private funds come from each filer's current regulatory profile. Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.

Excluded 5 holders with no observed 2026-03-31 13F and 7 holders with no observed 2026-06-30 13F. Compared across CIK changes: 4 filers continue as Evelyn Partners Group Ltd; JANUS HENDERSON GROUP PLC continues as Jupiter Topco LLC.

Showing 100 of 829
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Holder Value (USD) % of 13F Shares Open

Showing the top 100 of 829 holders. Create a free account to see every holder, past quarters, search, filters and CSV export.

Key facts CIK 1178670 CUSIP 02043Q107 13F (30d) 85 filings 79 filers Visit website Investor relations