216.80 USD
↘ 0.35 (0.16%)AFTER HOURS (AS OF Fri 07:31 PM EDT)
BIIB Stock After Hours
Biogen Inc. Common Stock
BIIBNASDAQ • USD
Market: CLOSED
After-hours trading runs 4:00 PM – 8:00 PM ET.
BIIB last traded at $216.80 after hours, down $0.35 (0.16%) from its regular-session close of $217.15.
📅 BIIB is expected to report earnings around Oct 29, 2026 before the open (estimated), with an estimated EPS of $2.03. BIIB earnings details →
BIIB After Hours Chart
BIIB After Hours News
Gap Analytics — 5-year history, 5% minimum gap
Over the past 5 years, BIIB has had 7 qualifying gap events (gaps of 5% or more at the open) — 3 gap-ups and 4 gap-downs. Gap-ups averaged +17.7%, 67% have fully filled, median time to fill 3 trading days. Gap-downs averaged -6.3%, 25% have fully filled, median time to fill 1 trading day. Most recent: a -5.3% gap down on Oct 30, 2025, which filled in 1 trading day. Average 20-trading-day return after a BIIB gap up: -3.68%. After a gap down: +4.36%.
Gap Ups3 events
Fill Rate
66.7%
Avg Gap
17.7%
Avg 50% Fill
2d
Avg Fill
3d
Gap Downs4 events
Fill Rate
25.0%
Avg Gap
6.3%
Avg 50% Fill
2d
Avg Fill
1d
Avg Gap Fill by Timeframes
Gap Ups
| 1 day | 1 week | 2 week | 4 week | |
|---|---|---|---|---|
| fills 25% | 67% | 100% | 100% | 100% |
| fills 50% | 33% | 67% | 67% | 67% |
| fills 75% | 33% | 67% | 67% | 67% |
| fills 100% | 0% | 67% | 67% | 67% |
Gap Downs
| 1 day | 1 week | 2 week | 4 week | |
|---|---|---|---|---|
| fills 25% | 50% | 100% | 100% | 100% |
| fills 50% | 25% | 75% | 75% | 75% |
| fills 75% | 25% | 50% | 50% | 50% |
| fills 100% | 25% | 25% | 25% | 25% |
Complete Gap History — 7 events
| Date | Gap From | Gap % | Status | Days to 50% | Days to Fill | % of Gap Filled After | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 day | 1 week | 2 week | 4 week | ||||||
| 2025-10-30 | $147.86 | -5.25% | Filled | 1d | 1d | 100% | 100% | 100% | 100% |
| 2025-07-31 | $126.64 | +5.02% | Filled | 1d | 2d | 91% | 100% | 100% | 100% |
| 2024-07-26 | $227.44 | -7.06% | Open | 5d | — | 38% | 50% | 50% | 50% |
| 2022-11-30 | $291.41 | +5.10% | Filled | 3d | 4d | 34% | 100% | 100% | 100% |
| 2022-09-28 | $197.79 | +43.06% | Open | — | — | 21% | 30% | 38% | 38% |
| 2022-01-12 | $241.52 | -7.63% | Open | 2d | — | 24% | 90% | 90% | 90% |
| 2021-12-30 | $258.31 | -5.08% | Open | — | — | 14% | 29% | 29% | 29% |
Frequently Asked Questions
What is BIIB's after-hours price?
Biogen (BIIB) is trading at $216.80 after hours, down $0.35 (0.16%) from its regular-session close of $217.15.
Why is BIIB moving after hours?
BIIB is down 0.16% in after-hours trading. Moves in this session almost always follow something released after the 4:00 PM ET close — an earnings report, guidance, a filing, or news — and trade on far thinner volume than the regular session, so the size of the move can overstate what the market will settle on at the next open.
When does BIIB after-hours trading start and end?
After-hours trading in BIIB on the NASDAQ runs from 4:00 PM to 8:00 PM ET on trading days, immediately after the regular session closes. Not every broker offers the full window, and liquidity thins sharply after about 6:30 PM ET.
Will BIIB's after-hours move hold at the open?
An after-hours move that carries into the next session becomes an opening gap, and BIIB's gap history is the best guide to what happens next: 67% of BIIB gap-ups have fully filled, and 25% of gap-downs have filled over the past 5 years. Fill rates this high mean a large after-hours move is more often faded than extended.
When does BIIB report earnings?
BIIB is expected to report earnings around Oct 29, 2026 before the open (estimated), with an estimated EPS of $2.03. Earnings are the most common cause of a large after-hours move, since most companies report after the close.