Primecap Management CO Biogen Inc. Transaction History

Primecap Management CO

$126 Billion
Q3 2025

A detailed history of Primecap Management CO transactions in Biogen Inc. stock. As of the latest transaction made, Primecap Management CO holds 14,954,697 shares of BIIB stock, worth $2.51 Billion. This represents 1.66% of its overall portfolio holdings.

Number of Shares

14,954,697

Previous 15,802,122 5.36%

Holding current value

$2.51 Billion

Previous $1.98 Billion 5.56%

% of portfolio

1.66%

Previous 1.62%

33 transactions

Quarter	Operation	Price Per share	shares change	shares Held
Q3 2025 Nov 10, 2025	SELL	$122.68 - $148.84 $104 Million - $126 Million	-847,425 Reduced 5.36%	14,954,697 $2.09 Billion
Q2 2025 Aug 11, 2025	SELL	$113.38 - $135.49 $16 Million - $19.1 Million	-141,137 Reduced 0.89%	15,802,122 $1.98 Billion
Q1 2025 May 09, 2025	SELL	$133.43 - $153.27 $13.7 Million - $15.8 Million	-102,950 Reduced 0.64%	15,943,259 $2.18 Billion
Q4 2024 Feb 10, 2025	SELL	$146.47 - $191.55 $39.4 Million - $51.5 Million	-268,870 Reduced 1.65%	16,046,209 $2.45 Billion
Q3 2024 Nov 08, 2024	SELL	$189.07 - $236.8 $4.39 Million - $5.5 Million	-23,215 Reduced 0.14%	16,315,079 $3.16 Billion

Q2 2024 Aug 09, 2024	BUY	$190.52 - $236.72 $22.4 Million - $27.8 Million	117,578 Added 0.72%	16,338,294 $3.79 Billion
Q1 2024 May 13, 2024	SELL	$212.02 - $267.71 $9.28 Million - $11.7 Million	-43,765 Reduced 0.27%	16,220,716 $3.5 Billion
Q4 2023 Feb 09, 2024	BUY	$222.59 - $267.94 $56.1 Million - $67.5 Million	251,915 Added 1.57%	16,264,481 $4.21 Billion
Q3 2023 Nov 13, 2023	SELL	$253.3 - $285.89 $3.37 Million - $3.81 Million	-13,310 Reduced 0.08%	16,012,566 $4.12 Billion
Q2 2023 Aug 11, 2023	BUY	$275.25 - $318.06 $6.8 Million - $7.86 Million	24,710 Added 0.15%	16,025,876 $4.56 Billion
Q1 2023 May 15, 2023	BUY	$256.56 - $292.34 $77.1 Million - $87.9 Million	300,590 Added 1.91%	16,001,166 $4.45 Billion
Q4 2022 Feb 13, 2023	SELL	$252.44 - $306.72 $10.4 Million - $12.6 Million	-41,139 Reduced 0.26%	15,700,576 $4.35 Billion
Q3 2022 Nov 14, 2022	BUY	$194.69 - $268.46 $2.96 Million - $4.08 Million	15,189 Added 0.1%	15,741,715 $4.2 Billion
Q2 2022 Aug 11, 2022	SELL	$187.54 - $223.02 $20.3 Million - $24.1 Million	-108,080 Reduced 0.68%	15,726,526 $3.21 Billion
Q1 2022 May 11, 2022	BUY	$193.77 - $244.14 $15 Million - $18.8 Million	77,201 Added 0.49%	15,834,606 $3.33 Billion
Q4 2021 Feb 11, 2022	SELL	$223.92 - $287.77 $112 Million - $144 Million	-501,510 Reduced 3.08%	15,757,405 $3.78 Billion
Q3 2021 Nov 12, 2021	SELL	$282.99 - $369.05 $56.5 Million - $73.7 Million	-199,591 Reduced 1.21%	16,258,915 $4.6 Billion
Q2 2021 Aug 10, 2021	SELL	$259.0 - $414.71 $77.6 Million - $124 Million	-299,750 Reduced 1.79%	16,458,506 $5.7 Billion
Q1 2021 May 14, 2021	BUY	$242.95 - $284.63 $227 Million - $266 Million	936,190 Added 5.92%	16,758,256 $4.69 Billion
Q4 2020 Feb 08, 2021	BUY	$236.26 - $355.63 $29.6 Million - $44.6 Million	125,362 Added 0.8%	15,822,066 $3.87 Billion
Q3 2020 Nov 13, 2020	BUY	$264.77 - $305.71 $17.1 Million - $19.8 Million	64,772 Added 0.41%	15,696,704 $4.45 Billion
Q2 2020 Aug 13, 2020	SELL	$258.66 - $342.55 $86.4 Million - $114 Million	-334,057 Reduced 2.09%	15,631,932 $4.18 Billion
Q1 2020 May 14, 2020	BUY	$268.85 - $341.04 $209 Million - $265 Million	776,508 Added 5.11%	15,965,989 $5.05 Billion
Q4 2019 Feb 14, 2020	BUY	$220.06 - $304.07 $205 Million - $283 Million	929,469 Added 6.52%	15,189,481 $4.51 Billion
Q3 2019 Nov 13, 2019	SELL	$217.44 - $243.88 $63.9 Million - $71.7 Million	-293,990 Reduced 2.02%	14,260,012 $3.32 Billion
Q2 2019 Aug 14, 2019	SELL	$219.29 - $241.72 $7.1 Million - $7.83 Million	-32,380 Reduced 0.22%	14,554,002 $3.4 Billion
Q1 2019 May 14, 2019	SELL	$216.71 - $338.96 $28.1 Million - $44 Million	-129,835 Reduced 0.88%	14,586,382 $3.45 Billion
Q4 2018 Feb 12, 2019	SELL	$278.5 - $352.75 $43.9 Million - $55.6 Million	-157,579 Reduced 1.06%	14,716,217 $4.43 Billion
Q3 2018 Nov 13, 2018	SELL	$293.51 - $383.83 $14.1 Million - $18.5 Million	-48,140 Reduced 0.32%	14,873,796 $5.26 Billion
Q2 2018 Aug 13, 2018	SELL	$257.52 - $306.91 $8.06 Million - $9.6 Million	-31,295 Reduced 0.21%	14,921,936 $4.33 Billion
Q1 2018 May 14, 2018	SELL	$260.13 - $367.91 $40.6 Million - $57.4 Million	-156,000 Reduced 1.03%	14,953,231 $4.09 Billion
Q4 2017 Feb 13, 2018	SELL	$307.64 - $344.58 $31.9 Million - $35.7 Million	-103,683 Reduced 0.68%	15,109,231 $4.81 Billion
Q3 2017 Nov 13, 2017	BUY	$281.15 - $329.69 $4.28 Billion - $5.02 Billion	15,212,914	15,212,914 $4.76 Billion

Others Institutions Holding BIIB

# of Institutions

1,073

Shares Held

131M

Call Options Held

3.77M

Put Options Held

2.31M

View Full List

About BIOGEN INC.

Ticker BIIB
Exchange NASDAQ
Sector Healthcare
Industry Drug Manufacturers—General
Shares Outstandng 144,000,992
Market Cap $24.1B
Description
Biogen Inc. discovers, develops, manufactures, and delivers therapies for treating neurological and neurodegenerative diseases. The company offers TECFIDERA, VUMERITY, AVONEX, PLEGRIDY, TYSABRI, and FAMPYRA for multiple sclerosis (MS); SPINRAZA for spinal muscular atrophy; and FUMADERM to treat plaque psoriasis. It also provides BENEPALI, an eta...

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Primecap Management CO Biogen Inc. Transaction History