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Portolan Capital Management, LLC

Position in BIIB — Biogen Inc.

CIK 1350290 BOSTON, MA

Position in BIIB

as of Jun 30, 2026 · filed Aug 14, 2026
Position Value
$30,865,467
+$9,144,346 QoQ
Shares Held
142,856
+20.6% QoQ
Ownership
0.097%
of shares outstanding
% of Portfolio
1.16%
of 13F equity value
Holder Rank
#82
of 1,036 holders
Holding Since
Dec 2025
3 quarters on record
Voting authority Sole 100% Shared 0% None 0%

Common Shares in BIIB Over Time

Shares Held

Position Value (USD)

Position in Drug Manufacturers - General

Healthcare · as of Jun 30, 2026

Portolan Capital Management, LLC holds $30,865,467 across 1 Drug Manufacturers - General name. BIIB ranks #1 (100.0% of the industry book) .

# Ticker Company Shares Value (USD) Open
1 BIIB
Biogen Inc.
This page
142,856 $30,865,467

All Filings in BIIB

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3 filing rows on record
Report Date Value (USD) Shares
2026-06-30 $30,865,467 142,856
2026-03-31 $21,721,121 118,481
2025-12-31 $14,957,390 84,990