Rhenman & Partners Asset Management’s Biogen BIIB Stock Holding History

Rhenman & Partners 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	$20M	Buy	109,100 +16,750	+18%	+$3.09M	2.47%	8
2025 Q4	$16.3M	Buy	92,350 +37,350	+68%	+$6.1M	1.52%	26
2025 Q3	$7.7M	Buy	55,000 +43,000	+358%	+$5.81M	0.85%	41
2025 Q2	$1.51M	Sell	12,000 -37,500	-76%	-$4.67M	0.19%	78
2025 Q1	$6.77M	Sell	49,500 -74,200	-60%	-$10.6M	0.78%	41
2024 Q4	$18.9M	Buy	123,700 +56,600	+84%	+$9.55M	1.94%	19
2024 Q3	$13M	Sell	67,100 -17,700	-21%	-$3.7M	1.06%	34
2024 Q2	$19.7M	Buy	84,800 +28,000	+49%	+$6.09M	1.89%	19
2024 Q1	$12.2M	Sell	56,800 -1,872	-3%	-$438K	1.16%	30
2023 Q4	$15.2M	Buy	58,672 +2,172	+4%	+$533K	1.52%	25
2023 Q3	$14.5M	Sell	56,500 -8,000	-12%	-$2.14M	1.57%	27
2023 Q2	$18.4M	Buy	64,500 +17,000	+36%	+$5.06M	1.94%	21
2023 Q1	$13.1M	Buy	47,500 +17,500	+58%	+$4.84M	1.43%	26
2022 Q4	$8.31M	Sell	30,000 -2,782	-8%	-$786K	0.87%	46
2022 Q3	$9.29M	Buy	+32,782	New	+$6.96M	0.97%	37
2022 Q2	–	Sell	-15,000	Closed	-$3.16M	–	88
2022 Q1	$3.16M	Sell	15,000 -100,000	-87%	-$21.7M	0.31%	77
2021 Q4	$27.6M	Sell	115,000 -35,000	-23%	-$9M	1.84%	18
2021 Q3	$42.4M	Buy	150,000 +60,000	+67%	+$19.7M	2.98%	6
2021 Q2	$31.2M	Buy	90,000 +70,500	+362%	+$21.4M	2.12%	10
2021 Q1	$5.46M	Sell	19,500 -20,500	-51%	-$5.53M	0.38%	71
2020 Q4	$9.79M	Buy	40,000 +7,000	+21%	+$1.81M	0.8%	52
2020 Q3	$9.36M	Buy	33,000 +16,000	+94%	+$4.46M	0.83%	48
2020 Q2	$4.55M	Sell	17,000 -8,000	-32%	-$2.4M	0.49%	66
2020 Q1	$7.91M	Buy	25,000 +5,000	+25%	+$1.52M	1.11%	42
2019 Q4	$5.93M	Buy	+20,000	New	+$5.55M	0.65%	59
2019 Q1	–	Sell	-60,000	Closed	-$18.1M	–	94
2018 Q4	$18.1M	Buy	60,000 +30,000	+100%	+$9.57M	2.06%	17
2018 Q3	$10.6M	Buy	30,000 +17,000	+131%	+$5.85M	1.06%	44
2018 Q2	$3.77M	Sell	13,000 -29,300	-69%	-$8.24M	0.39%	64
2018 Q1	$11.6M	Buy	42,300 +27,000	+176%	+$8.38M	1.43%	31
2017 Q4	$4.87M	Sell	15,300 -6,700	-30%	-$2.15M	0.66%	56
2017 Q3	$6.89M	Sell	22,000 -26,500	-55%	-$7.85M	0.88%	44
2017 Q2	$13.2M	Sell	48,500 -19,500	-29%	-$5.16M	1.89%	18
2017 Q1	$18.6M	Buy	68,000 +32,000	+89%	+$9.05M	2.94%	3
2016 Q4	$10.2M	Sell	36,000 -21,000	-37%	-$6.22M	1.96%	17
2016 Q3	$17.8M	Sell	57,000 -23,000	-29%	-$6.81M	2.83%	8
2016 Q2	$19.3M	Buy	80,000 +42,000	+111%	+$11.1M	3.44%	4
2016 Q1	$9.89M	Buy	+38,000	New	+$10M	1.96%	14
2015 Q3	–	Sell	-50,291	Closed	-$20.3M	–	93
2015 Q2	$20.3M	Buy	50,291 +9,591	+24%	+$3.85M	2.44%	6
2015 Q1	$17.2M	Buy	40,700 +19,200	+89%	+$7.57M	2.9%	5
2014 Q4	$7.3M	Sell	21,500 -7,500	-26%	-$2.43M	2.12%	8
2014 Q3	$9.59M	Sell	29,000 -21,000	-42%	-$6.92M	2.81%	5
2014 Q2	$15.8M	Buy	50,000 +8,952	+22%	+$2.69M	4.68%	1
2014 Q1	$12.6M	Buy	41,048 +14,048	+52%	+$4.46M	3.77%	4
2013 Q4	$7.55M	Buy	+27,000	New	+$6.98M	2.95%	5

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

Rhenman & Partners Asset Management's BIIB Position: Q1 2026 in Review

Rhenman & Partners Asset Management increased its Biogen (BIIB) stake by 18% in Q1 2026, buying an estimated $3.09M and bringing the position to 109,100 shares worth $20M. The position accounts for 2.47% of the portfolio, ranked #8.

Rhenman & Partners Asset Management first reported a position in BIIB in Q4 2013 and has held it in 44 quarters since. The position peaked at $42.4M in Q3 2021. 1,004 funds tracked by Wall St. Rank hold BIIB as of Q1 2026.

Rhenman & Partners Asset Management held 109,100 shares of Biogen worth $20M as of Q1 2026.
Rhenman & Partners Asset Management bought 16,750 Biogen shares in Q1 2026, an estimated $3.09M.
Biogen made up 2.47% of Rhenman & Partners Asset Management's portfolio in Q1 2026, its #8 holding.
Rhenman & Partners Asset Management first reported a position in Biogen in Q4 2013 and has held it in 44 quarters since.
Rhenman & Partners Asset Management's Biogen position peaked at $42.4M in Q3 2021.
1,004 funds tracked by Wall St. Rank held Biogen as of Q1 2026.

Based on Rhenman & Partners Asset Management's 13F filing for Q1 2026, filed 14 May 2026.