Alnylam Pharmaceuticals, Inc.: which funds bought and sold

Institutions that bought and sold Alnylam Pharmaceuticals shares in Q2 2026, from the holdings they reported to the SEC on Form 13F for March 31, 2026 and June 30, 2026.

Between March 31, 2026 and June 30, 2026, 400 institutions that filed 13F reports for both quarters added to or opened positions in Alnylam Pharmaceuticals, and 358 cut or closed them. Together they sold a net 90K shares, −0.1% on what they held at the start of the quarter. Active managers and hedge funds on our list were net buyers of 2.0M shares (+3.0%); index fund managers were net buyers of 863K shares (+2.7%). 77 opened a new position and 80 sold out entirely.

Bought, Q2 2026 400 institutions, 77 of them new holders Sold, Q2 2026 358 institutions, 80 of them sold out

Net change, all compared −90K shares (−0.1%)

Net change, active managers +2.0M shares (+3.0%), 49 bought, 38 sold

Buyers versus sellers

institutions compared, 852

400 bought 94 358 sold

Active managers and hedge funds 49 bought · 38 sold · +2.0M

Index fund managers 8 bought · 4 sold · +863K

Other institutions 343 bought · 316 sold · −2.9M

Biggest buyers

by change in shares held

Biggest buyers
Institution	Change in shares	Shares June 30, 2026	Value
Deep Track Capital, LP Hedge fund	+825K New position	825K	$248M
Orbis Allan Gray Ltd Active manager	+653K +48.9%	2.0M	$598M
Los Angeles Capital Management LLC Active manager	+641K +726.5%	730K	$220M
Paradigm Biocapital Advisors LP	+480K New position	480K	$144M
Blackrock, Inc. Index funds	+463K +4.4%	10.9M	$3.3B
T. Rowe Price Investment Management, Inc. Active manager	+449K +8.6%	5.6M	$1.7B
FMR LLC Active manager	+445K +3.1%	15.0M	$4.5B
Capital World Investors Active manager	+342K +3.2%	11.1M	$3.4B
Capital Research Global Investors Active manager	+280K +3.0%	9.8M	$2.9B
State Street Corp Index funds	+233K +7.0%	3.6M	$1.1B
Manufacturers Life Insurance Company, The	+231K +34.9%	894K	$269M
Polar Capital Holdings PLC Active manager	+225K +87.3%	483K	$145M
Assenagon Asset Management S.A.	+182K +141.6%	311K	$93.7M
Wellington Management Group LLP Active manager	+174K +9.0%	2.1M	$635M
UBS Group AG	+168K +36.6%	627K	$189M
Citadel Advisors LLC Hedge fund	+168K +715.8%	191K	$57.5M
Canada Pension Plan Investment Board	+125K +60.0%	334K	$101M
Susquehanna International Group, LLP	+120K +69.0%	294K	$88.6M
Vinva Investment Management Ltd	+118K +323.4%	155K	$45.5M
Davern Capital Partners, LP	+113K New position	113K	$34M

Biggest buyers, active managers and hedge funds
Institution	Change in shares	Shares June 30, 2026	Value
Deep Track Capital, LP Hedge fund	+825K New position	825K	$248M
Orbis Allan Gray Ltd Active manager	+653K +48.9%	2.0M	$598M
Los Angeles Capital Management LLC Active manager	+641K +726.5%	730K	$220M
T. Rowe Price Investment Management, Inc. Active manager	+449K +8.6%	5.6M	$1.7B
FMR LLC Active manager	+445K +3.1%	15.0M	$4.5B
Capital World Investors Active manager	+342K +3.2%	11.1M	$3.4B
Capital Research Global Investors Active manager	+280K +3.0%	9.8M	$2.9B
Polar Capital Holdings PLC Active manager	+225K +87.3%	483K	$145M
Wellington Management Group LLP Active manager	+174K +9.0%	2.1M	$635M
Citadel Advisors LLC Hedge fund	+168K +715.8%	191K	$57.5M

Biggest sellers

by change in shares held

Biggest sellers
Institution	Change in shares	Shares June 30, 2026	Value
Jpmorgan Chase & Co	−3.6M −57.7%	2.7M	$785M
Marshall Wace, LLP Hedge fund	−840K −76.4%	260K	$78.2M
Invesco Ltd.	−321K −7.9%	3.8M	$1.1B
Price T Rowe Associates Inc Active manager	−284K −19.8%	1.1M	$346M
Allspring Global Investments Holdings, LLC	−279K −99.1%	2,546	$768,052
Bellevue Group AG	−233K −99.5%	1,092	$328,725
Squarepoint Ops LLC Hedge fund	−193K −45.2%	234K	$70.4M
AQR Capital Management LLC Hedge fund	−185K −20.3%	728K	$219M
Voloridge Investment Management, LLC Hedge fund	−185K −97.6%	4,500	$1.4M
Jacobs Levy Equity Management, Inc Active manager	−151K −71.3%	61K	$18.4M
Massachusetts Financial Services Co Active manager	−145K −29.3%	351K	$106M
Millennium Management LLC Hedge fund	−132K −29.4%	316K	$95.1M
Amundi	−130K −17.4%	617K	$186M
HRT Financial LP	−129K Sold out	0	—
Two Sigma Investments, LP Hedge fund	−117K −5.9%	1.9M	$565M
Orbimed Advisors LLC	−102K −85.7%	17K	$5.1M
Soleus Capital Management, L.P. Hedge fund	−99K −74.9%	33K	$9.9M
Clearbridge Investments, LLC Active manager	−97K −7.1%	1.3M	$379M
Barclays PLC	−85K −38.6%	136K	$40.8M
Pinebridge Investments LLC	−76K −27.9%	196K	$58.9M

Biggest sellers, active managers and hedge funds
Institution	Change in shares	Shares June 30, 2026	Value
Marshall Wace, LLP Hedge fund	−840K −76.4%	260K	$78.2M
Price T Rowe Associates Inc Active manager	−284K −19.8%	1.1M	$346M
Squarepoint Ops LLC Hedge fund	−193K −45.2%	234K	$70.4M
AQR Capital Management LLC Hedge fund	−185K −20.3%	728K	$219M
Voloridge Investment Management, LLC Hedge fund	−185K −97.6%	4,500	$1.4M
Jacobs Levy Equity Management, Inc Active manager	−151K −71.3%	61K	$18.4M
Massachusetts Financial Services Co Active manager	−145K −29.3%	351K	$106M
Millennium Management LLC Hedge fund	−132K −29.4%	316K	$95.1M
Two Sigma Investments, LP Hedge fund	−117K −5.9%	1.9M	$565M
Soleus Capital Management, L.P. Hedge fund	−99K −74.9%	33K	$9.9M

New positions

largest by value

Institution	Shares	Value June 30, 2026
Deep Track Capital, LPHedge fund	825K	$248M
Paradigm Biocapital Advisors LP	480K	$144M
Davern Capital Partners, LP	113K	$34M
Longaeva Partners L.P.	110K	$33.2M
Balyasny Asset Management L.P.Hedge fund	90K	$26.9M
Arrowstreet Capital, Limited PartnershipHedge fund	50K	$14.9M
Mn Services Vermogensbeheer B.V.	39K	$11.7M
J. Goldman & Co LPHedge fund	39K	$11.6M
Catalyst Funds Management Pty Ltd	21K	$6.3M
Kornitzer Capital Management Inc	17K	$5.2M

Sold out

largest by value

Institution	Shares	Value March 31, 2026
HRT Financial LP	129K	$42.6M
Parnassus Investments, LLCActive manager	49K	$16.2M
Fenghe Fund Management Pte. Ltd.	33K	$10.8M
Varma Mutual Pension Insurance Co	21K	$7M
Thrivent Financial For Lutherans	20K	$6.8M
Public Sector Pension Investment Board	18K	$6M
Silvercrest Asset Management Group LLC	10K	$3.5M
Edgestream Partners, L.P.Hedge fund	5,810	$1.9M
Susquehanna Portfolio Strategies, LLC	5,005	$1.7M
Draper Asset Management, LLC	3,773	$1.2M

Who holds the shares

13F holdings at June 30, 2026

Institutions reporting: 782
Ten largest holders: 56.2%
Index fund managers: 24.4%
Active managers and hedge funds: 50.7%

Buying and selling by type of institution, March 31, 2026 to June 30, 2026
Type	Bought	Sold	New	Sold out	Net change in shares	Net %
Active managers and hedge funds	49	38	10	4	+2.0M	+3.0%
Index fund managers	8	4	0	0	+863K	+2.7%
Other institutions	343	316	67	76	−2.9M	−8.6%

Active managers and hedge funds: a list we maintain of about 400 well-known stock-picking firms and hedge funds, matched by SEC registration number (CIK) and checked against the filer names each quarter. Index fund managers: the large index houses, such as BlackRock, Vanguard, State Street, Geode and Northern Trust. Every other filer (banks, brokers, wealth managers, pension funds, insurers and firms not on the list) counts as another institution. A firm that files under several SEC registrations appears once for each.

What these filings can and cannot tell you

Form 13F lists the long positions in US-listed shares held by investment managers with more than $100 million in such holdings. Managers file it up to 45 days after each quarter ends, so this page shows what funds held at the end of each quarter, not what they are doing now: a position may have changed since. Short positions, most derivatives and smaller managers are not included, and a cut can mean a fund lost clients or rebalanced rather than a view on Alnylam Pharmaceuticals.

Only managers that filed a holdings report for both quarters are compared (852 here). 23 other holders are left out: first-time or late filers, firms that changed their SEC registration, and filings that withheld positions under confidential treatment, any of which would otherwise look like a new position or a sale. Figures are as reported by each manager in the SEC's quarterly 13F data sets; option positions are excluded.

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