Calamos Advisors’s Biogen BIIB Stock Holding History

Calamos Advisors’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
2020 Q1	–	Sell	-26,200	Closed	-$7.77M	–	713
2019 Q4	$7.77M	Buy	+26,200	New	+$7.27M	0.04%	415
2018 Q4	–	Sell	-37,900	Closed	-$13.4M	–	675
2018 Q3	$13.4M	Buy	+37,900	New	+$13M	0.07%	280
2015 Q3	–	Sell	-1,078	Closed	-$2.46M	–	680
2015 Q2	$2.46M	Sell	1,078 -105	-9%	-$42.1K	0.02%	455
2015 Q1	$3.38M	Buy	+1,183	New	+$466K	0.02%	427

Other funds holding BIIB

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return

Norges Bank Oslo, Norway $1T AUM

Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return

Calamos Advisors's BIIB Position: Q2 2026 in Review

Calamos Advisors reduced its Biogen (BIIB) stake by 1.8% in Q2 2026, selling an estimated $124K and leaving 34,879 shares worth $7.54M. The position accounts for 0.03% of the portfolio, ranked #476.

Calamos Advisors first reported a position in BIIB in Q2 2013 and has held it in 53 quarters since. The position peaked at $125M in Q2 2015. 1,043 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

Calamos Advisors held 34,879 shares of Biogen worth $7.54M as of Q2 2026.
Calamos Advisors sold 648 Biogen shares in Q2 2026, an estimated $124K.
Biogen made up 0.03% of Calamos Advisors's portfolio in Q2 2026, its #476 holding.
Calamos Advisors first reported a position in Biogen in Q2 2013 and has held it in 53 quarters since.
Calamos Advisors's Biogen position peaked at $125M in Q2 2015.
1,043 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

Based on Calamos Advisors's 13F filing for Q2 2026, filed 31 Jul 2026.