Rock Springs Capital Management’s Biogen BIIB Stock Holding History

Rock Springs Capital 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
2021 Q3	–	Sell	-113,500	Closed	-$39.3M	–	158
2021 Q2	$39.3M	Hold	113,500	–	–	0.78%	44
2021 Q1	$31.8M	Buy	113,500 +13,500	+14%	+$3.64M	0.69%	48
2020 Q4	$24.5M	Sell	100,000 -72,500	-42%	-$18.7M	0.52%	67
2020 Q3	$48.9M	Sell	172,500 -7,500	-4%	-$2.09M	1.24%	26
2020 Q2	$48.2M	Hold	180,000	–	–	1.32%	21
2020 Q1	$56.9M	Buy	+180,000	New	+$54.6M	2.35%	4
2019 Q1	–	Sell	-50,000	Closed	-$15.7M	–	132
2018 Q4	$15M	Hold	50,000	–	–	0.71%	44
2018 Q3	$17.7M	Sell	50,000 -3,000	-6%	-$1.03M	0.64%	54
2018 Q2	$15.4M	Hold	53,000	–	–	0.59%	64
2018 Q1	$14.5M	Hold	53,000	–	–	0.62%	61
2017 Q4	$16.9M	Hold	53,000	–	–	0.77%	43
2017 Q3	$16.6M	Hold	53,000	–	–	0.77%	50
2017 Q2	$14.4M	Buy	53,000 +5,000	+10%	+$1.32M	0.73%	49
2017 Q1	$13.1M	Buy	48,000 +1,000	+2%	+$283K	0.76%	47
2016 Q4	$13.3M	Sell	47,000 -11,000	-19%	-$3.26M	0.89%	38
2016 Q3	$18.2M	Buy	58,000 +350	+0.6%	+$104K	1.14%	29
2016 Q2	$13.9M	Buy	57,650 +4,500	+8%	+$1.19M	1.03%	34
2016 Q1	$13.8M	Buy	53,150 +2,500	+5%	+$660K	1.16%	27
2015 Q4	$15.5M	Buy	50,650 +12,000	+31%	+$3.45M	1.18%	26
2015 Q3	$11.3M	Hold	38,650	–	–	0.92%	36
2015 Q2	$15.6M	Buy	38,650 +1,650	+4%	+$662K	1.14%	29
2015 Q1	$15.6M	Sell	37,000 -8,500	-19%	-$3.35M	1.46%	25
2014 Q4	$15.4M	Sell	45,500 -15,850	-26%	-$5.13M	1.81%	16
2014 Q3	$20.3M	Buy	61,350 +1,350	+2%	+$445K	3.14%	9
2014 Q2	$18.9M	Buy	60,000 +4,750	+9%	+$1.43M	3.39%	6
2014 Q1	$16.9M	Buy	55,250 +2,250	+4%	+$714K	3.9%	4
2013 Q4	$14.8M	Buy	+53,000	New	+$13.7M	5.3%	3

Other funds holding BIIB

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

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

Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return

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

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

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

ClearBridge Investments New York $115B AUM 24.78% 1-Year Est. Return

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

T. Rowe Price Associates Baltimore, Maryland $865B AUM 30.76% 1-Year Est. Return

Northern Trust Chicago, Illinois $757B AUM 28.64% 1-Year Est. Return

Rock Springs Capital Management's BIIB Position: Q3 2021 in Review

Rock Springs Capital Management sold out of Biogen (BIIB) in Q3 2021, closing a stake of 113,500 shares — an estimated $39.3M sold.

Rock Springs Capital Management first reported a position in BIIB in Q4 2013 and held it in 27 quarters. The position peaked at $56.9M in Q1 2020. 1,040 funds tracked by Wall St. Rank hold BIIB as of Q3 2021.

Rock Springs Capital Management reported no remaining Biogen position as of Q3 2021 after selling out during the quarter.
Rock Springs Capital Management sold 113,500 Biogen shares in Q3 2021, an estimated $39.3M.
Rock Springs Capital Management first reported a position in Biogen in Q4 2013 and held it in 27 quarters.
Rock Springs Capital Management's Biogen position peaked at $56.9M in Q1 2020.
1,040 funds tracked by Wall St. Rank held Biogen as of Q3 2021.

Based on Rock Springs Capital Management's 13F filing for Q3 2021, filed 15 Nov 2021.