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Livermore
Livermore
ZHEN

Citadel Advisors LLC

SEC CIK
0001423053
Latest filing
Sep 1, 2026

BIIB holding history

Biogen Inc. in every 13F filed by Citadel Advisors LLC, including the quarters it was sold out or no filing was made. Changes compare share counts with the previous calendar quarter.

BIIB overviewAll 13F holders of BIIBFull Q2 2026 holdings

Shares (Q2 2026)
418,356
Value
$90.4M
% of portfolio
0.1%
Quarters held
20
Since Q1 2021
Holdings of BIIB by Citadel Advisors LLC, by quarter
QuarterSharesValue% of portfolioShare changeActionAll holders
Q2 2026418,356$90.4M0.1%+280,263+203.0%AddedHolders
Q1 2026138,093$25.3M<0.1%+97,669+241.6%AddedHolders
Q4 202540,424$7.11M<0.1%−332,304−89.2%ReducedHolders
Q3 2025372,728$52.2M<0.1%−235,862−38.8%ReducedHolders
Q2 2025608,590$76.4M0.1%+66,826+12.3%AddedHolders
Q1 2025541,764$74.1M0.1%+388,104+252.6%AddedHolders
Q4 2024153,660$23.5M<0.1%−218,706−58.7%ReducedHolders
Q3 2024372,366$72.2M0.1%+372,366NewHolders
Q2 20240$00.0%−149,298−100.0%Sold outHolders
Q1 2024149,298$32.2M<0.1%+144,037+2,737.8%AddedHolders
Q4 20235,261$1.36M<0.1%−72,875−93.3%ReducedHolders
Q3 202378,136$20.1M<0.1%+78,136NewHolders
Q2 20230$00.0%−245,084−100.0%Sold outHolders
Q1 2023245,084$68.1M0.1%−2,728−1.1%ReducedHolders
Q4 2022247,812$68.6M0.1%−1,566−0.6%ReducedHolders
Q3 2022249,378$66.6M0.1%+40,935+19.6%AddedHolders
Q2 2022208,443$42.5M0.1%+130,048+165.9%AddedHolders
Q1 202278,395$16.5M<0.1%−10,846−12.2%ReducedHolders
Q4 202189,241$21.4M<0.1%−247,115−73.5%ReducedHolders
Q3 2021336,356$95.2M0.1%−220,533−39.6%ReducedHolders
Q2 2021556,889$192.8M0.2%+333,326+149.1%AddedHolders
Q1 2021223,563$62.5M0.1%––Holders

Livermore's 13F data starts with Q1 2021, so Q1 2021 has no change from the previous quarter.