SIG Brokerage’s Biogen BIIB Stock Holding History

SIG Brokerage’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	$1.01M	Sell	5,500 -5,422	-50%	-$999K	0.03%	419
2025 Q4	$1.92M	Buy	10,922 +6,141	+128%	+$1M	0.06%	244
2025 Q3	$670K	Buy	4,781 +1,402	+41%	+$190K	0.02%	466
2025 Q2	$424K	Sell	3,379 -846	-20%	-$105K	0.01%	508
2025 Q1	$578K	Sell	4,225 -186	-4%	-$26.6K	0.03%	334
2024 Q4	$675K	Buy	+4,411	New	+$744K	0.04%	293

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

SIG Brokerage's BIIB Position: Q1 2026 in Review

SIG Brokerage reduced its Biogen (BIIB) stake by 50% in Q1 2026, selling an estimated $999K and leaving 5,500 shares worth $1.01M. The position accounts for 0.03% of the portfolio, ranked #419.

SIG Brokerage first reported a position in BIIB in Q4 2024 and has held it in 6 quarters since. The position peaked at $1.92M in Q4 2025. 1,002 funds tracked by Wall St. Rank hold BIIB as of Q1 2026.

SIG Brokerage held 5,500 shares of Biogen worth $1.01M as of Q1 2026.
SIG Brokerage sold 5,422 Biogen shares in Q1 2026, an estimated $999K.
Biogen made up 0.03% of SIG Brokerage's portfolio in Q1 2026, its #419 holding.
SIG Brokerage first reported a position in Biogen in Q4 2024 and has held it in 6 quarters since.
SIG Brokerage's Biogen position peaked at $1.92M in Q4 2025.
1,002 funds tracked by Wall St. Rank held Biogen as of Q1 2026.

Based on SIG Brokerage's 13F filing for Q1 2026, filed 15 May 2026.