Biogen Inc. (BIIB) Institutional Ownership & Insider Trading

1,041 institutions reported holding Biogen Inc. shares in 13F filings for the quarter ended 2026-06-30, according to EquiReason's reading of their SEC filings. 5 insider trades on Form 4 since 2025-10-01.

Source: SEC EDGAR filings · figures as of 2026-06-30 · read by EquiReason

BIIBBiogen Inc.Follow BIIB — free

Drug Manufacturers - General · Healthcare

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Market cap: 37.0B
P/E TTM: 44.5
Dividend yield: —
52-week: —
Next earnings: 28 Oct, in 4 days

Institutions · all 13F filers

quarter to 30 Jun 2026 · filers in both quarters

1,041 institutions held 96.3% of the shares. Across filers that reported both quarters, shares held changed +3.5%.

Largest moves, shares (millions)

Institutional flow by quarter

net shares added or trimmed, millions · filers in both quarters

Quarter	Holders	Shares held, M	Change	Increased	New	Decreased	Closed
Jun 26	1,041	142	+3.5%	372	86	252	59
Mar 26	993	134	-2.5%	344	95	251	79
Dec 25	978	139	+4.0%	282	120	263	55
Sep 25	873	132	+3.3%	278	85	226	53
Jun 25	849	129	+0.1%	313	62	230	78
Mar 25	858	127	-0.3%	293	83	239	86
Dec 24	840	131	-2.1%	266	53	291	132
Sep 24	884	126	-2.1%	232	68	318	96

Biogen Inc. — questions

Who owns Biogen Inc. stock?: 1,041 institutions reported Biogen Inc. shares in 13F filings for the quarter ended 2026-06-30. The largest: FMR LLC (12.3%), BlackRock, Inc. (10.8%), PRIMECAP MANAGEMENT CO/CA/ (10.3%).
Are Biogen Inc. insiders buying or selling?: 5 insider trades on Form 4 since 2025-10-01; the full list, with dates, people and plan status, is on this page.

Every figure on this page comes from Biogen Inc.'s own SEC filings — see them on SEC EDGAR. Price data is licensed and shown only inside the product.

How these figures are read: methodology · EquiReason.

Important information. Figures on this page are taken from filings submitted to the U.S. Securities and Exchange Commission (SEC) and processed automatically by EquiReason. They may contain errors, omissions or delays, and EquiReason makes no representation or warranty as to their accuracy, completeness or timeliness. Always verify figures against the original filing on SEC EDGAR before relying on them.

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