Weiss Asset Management’s Biogen BIIB Stock Holding History

Weiss Asset Management’s Portfolio BIIB Stock Details BIIB Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	–	Sell	-55,560	Closed	-$9.78M	–	533
2025 Q4	$9.78M	Buy	+55,560	New	+$9.08M	0.13%	131
2024 Q2	–	Sell	-1,554	Closed	-$335K	–	297
2024 Q1	$335K	Buy	+1,554	New	+$364K	0.01%	235
2021 Q3	–	Sell	-5,612	Closed	-$1.94M	–	507
2021 Q2	$1.94M	Buy	+5,612	New	+$1.7M	0.05%	305

Other funds holding BIIB

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

Primecap Management Pasadena, California $127B AUM 44.11% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return

Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return

Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return

JP Morgan Chase New York $1.56T AUM 27.86% 1-Year Est. Return

Weiss Asset Management's BIIB Position: Q1 2026 in Review

Weiss Asset Management sold out of Biogen (BIIB) in Q1 2026, closing a stake of 55,560 shares — an estimated $9.78M sold.

Weiss Asset Management first reported a position in BIIB in Q2 2021 and held it in 3 quarters. The position peaked at $9.78M in Q4 2025. 1,002 funds tracked by Wall St. Rank hold BIIB as of Q1 2026.

Weiss Asset Management reported no remaining Biogen position as of Q1 2026 after selling out during the quarter.
Weiss Asset Management sold 55,560 Biogen shares in Q1 2026, an estimated $9.78M.
Weiss Asset Management first reported a position in Biogen in Q2 2021 and held it in 3 quarters.
Weiss Asset Management's Biogen position peaked at $9.78M in Q4 2025.
1,002 funds tracked by Wall St. Rank held Biogen as of Q1 2026.

Based on Weiss Asset Management's 13F filing for Q1 2026, filed 15 May 2026.