CITADEL ADVISORS LLC's ownership history for BIIB

CITADEL ADVISORS LLC currently holds 138.1K shares with a market value of $25.3M. It started holding BIIB on 2024-09-30. At its peak, it held 608.6K shares on 2025-06-30. Its highest holding value was $76.4M on 2025-06-30. At its lowest, it held 40.4K shares on 2025-12-31, with a value of $7.1M on 2025-12-31. In the recent 180 days, CITADEL ADVISORS LLC has decreased its shares by 234.6K. In the recent year, CITADEL ADVISORS LLC has decreased its shares by 403.7K.

It has also owned 3.0K contracts of calls, with the market value of the underlying securities totaling $55.0M on 2024-09-30. At its peak, it held 4.7K contracts of calls on 2025-06-30 and it owned calls with the market value of the underlying securities totaling $71.6M on 2025-12-31. At its lowest, it held 1.1K contracts of calls on 2024-09-30 and it owned calls with the market value of the underlying securities totaling $20.9M on 2024-09-30. In the recent 180 days, CITADEL ADVISORS LLC has increased its holdings by 587 contracts. In the recent year, CITADEL ADVISORS LLC has increased its holdings by 938 contracts.

It has also owned 927 contracts of puts, with the market value of the underlying securities totaling $17.0M on 2024-09-30. At its peak, it held 10.0K contracts of puts on 2025-03-31 and it owned puts with the market value of the underlying securities totaling $136.6M on 2025-03-31. At its lowest, it held 927 contracts of puts on 2026-03-31 and it owned puts with the market value of the underlying securities totaling $17.0M on 2026-03-31. In the recent 180 days, CITADEL ADVISORS LLC has decreased its holdings by 653 contracts. In the recent year, CITADEL ADVISORS LLC has increased its holdings by 128.1K contracts.