Ken Griffin Biogen Inc. Transaction History

Citadel Advisors LLC

$618 Billion
Q3 2025

A detailed history of Ken Griffin (Citadel Advisors LLC) transactions in Biogen Inc. stock. As of the latest transaction made, Citadel Advisors LLC holds 372,728 shares of BIIB stock, worth $62.5 Million. This represents 0.01% of its overall portfolio holdings.

Number of Shares

372,728

Previous 608,590 38.76%

Holding current value

$62.5 Million

Previous $76.4 Million 31.69%

% of portfolio

0.01%

Previous 0.01%

31 transactions

Quarter	Operation	Price Per share	shares change	shares Held
Q3 2025 Nov 14, 2025	SELL	$122.68 - $148.84 $28.9 Million - $35.1 Million	-235,862 Reduced 38.76%	372,728 $52.2 Million
Q2 2025 Aug 14, 2025	BUY	$113.38 - $135.49 $7.58 Million - $9.05 Million	66,826 Added 12.33%	608,590 $76.4 Million
Q1 2025 May 15, 2025	BUY	$133.43 - $153.27 $51.8 Million - $59.5 Million	388,104 Added 252.57%	541,764 $74.1 Million
Q4 2024 Feb 14, 2025	SELL	$146.47 - $191.55 $32 Million - $41.9 Million	-218,706 Reduced 58.73%	153,660 $23.5 Million
Q3 2024 Nov 14, 2024	BUY	$189.07 - $236.8 $70.4 Million - $88.2 Million	372,366 New	372,366 $72.2 Million
Q1 2024 May 15, 2024	BUY	$212.02 - $267.71 $30.5 Million - $38.6 Million	144,037 Added 2737.83%	149,298 $32.2 Million
Q4 2023 Feb 14, 2024	SELL	$222.59 - $267.94 $16.2 Million - $19.5 Million	-72,875 Reduced 93.27%	5,261 $1.36 Million
Q3 2023 Nov 14, 2023	BUY	$253.3 - $285.89 $19.8 Million - $22.3 Million	78,136 New	78,136 $20.1 Million
Q1 2023 May 15, 2023	SELL	$256.56 - $292.34 $699,895 - $797,503	-2,728 Reduced 1.1%	245,084 $68.1 Million
Q4 2022 Feb 14, 2023	SELL	$252.44 - $306.72 $395,321 - $480,323	-1,566 Reduced 0.63%	247,812 $68.6 Million
Q3 2022 Nov 14, 2022	BUY	$194.69 - $268.46 $7.97 Million - $11 Million	40,935 Added 19.64%	249,378 $66.6 Million
Q2 2022 Aug 15, 2022	BUY	$187.54 - $223.02 $24.4 Million - $29 Million	130,048 Added 165.89%	208,443 $42.5 Million
Q1 2022 May 16, 2022	SELL	$193.77 - $244.14 $2.1 Million - $2.65 Million	-10,846 Reduced 12.15%	78,395 $16.5 Million
Q4 2021 Feb 14, 2022	SELL	$223.92 - $287.77 $55.3 Million - $71.1 Million	-247,115 Reduced 73.47%	89,241 $21.4 Million
Q3 2021 Nov 15, 2021	SELL	$282.99 - $369.05 $62.4 Million - $81.4 Million	-220,533 Reduced 39.6%	336,356 $95.2 Million
Q2 2021 Aug 16, 2021	BUY	$259.0 - $414.71 $86.3 Million - $138 Million	333,326 Added 149.1%	556,889 $193 Million
Q1 2021 May 17, 2021	SELL	$242.95 - $284.63 $30.7 Million - $36 Million	-126,331 Reduced 36.11%	223,563 $62.5 Million
Q4 2020 Feb 16, 2021	BUY	$236.26 - $355.63 $77.1 Million - $116 Million	326,285 Added 1382.04%	349,894 $85.7 Million
Q3 2020 Nov 16, 2020	SELL	$264.77 - $305.71 $30.4 Million - $35.1 Million	-114,656 Reduced 82.92%	23,609 $6.7 Million
Q2 2020 Aug 14, 2020	SELL	$258.66 - $342.55 $19.3 Million - $25.6 Million	-74,638 Reduced 35.06%	138,265 $37 Million
Q1 2020 May 15, 2020	SELL	$268.85 - $341.04 $4.49 Million - $5.69 Million	-16,694 Reduced 7.27%	212,903 $67.4 Million
Q4 2019 Feb 14, 2020	BUY	$220.06 - $304.07 $18.8 Million - $26 Million	85,415 Added 59.24%	229,597 $68.1 Million
Q3 2019 Nov 14, 2019	BUY	$217.44 - $243.88 $28.1 Million - $31.5 Million	129,073 Added 854.28%	144,182 $33.6 Million
Q2 2019 Aug 14, 2019	SELL	$219.29 - $241.72 $29.5 Million - $32.5 Million	-134,307 Reduced 89.89%	15,109 $3.53 Million
Q1 2019 May 15, 2019	BUY	$216.71 - $338.96 $2.87 Million - $4.49 Million	13,237 Added 9.72%	149,416 $0
Q4 2018 Feb 14, 2019	BUY	$278.5 - $352.75 $22.5 Million - $28.5 Million	80,679 Added 145.37%	136,179 $41 Million
Q3 2018 Nov 13, 2018	SELL	$293.51 - $383.83 $17.5 Million - $22.9 Million	-59,634 Reduced 51.8%	55,500 $0
Q2 2018 Aug 10, 2018	SELL	$257.52 - $306.91 $37.1 Million - $44.3 Million	-144,233 Reduced 55.61%	115,134 $0
Q1 2018 May 11, 2018	BUY	$260.13 - $367.91 $25.6 Million - $36.2 Million	98,403 Added 61.13%	259,367 $71 Million
Q4 2017 Feb 09, 2018	SELL	$307.64 - $344.58 $155 Million - $173 Million	-502,732 Reduced 75.75%	160,964 $51.3 Million
Q3 2017 Nov 09, 2017	BUY	$281.15 - $329.69 $187 Million - $219 Million	663,696	663,696 $208 Million

Others Institutions Holding BIIB

# of Institutions

1,070

Shares Held

128M

Call Options Held

3.03M

Put Options Held

2.24M

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...

More about BIIB

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