Biogen (BIIB): buy, hold or sell?
Genomics & AI-Health. One systematic signal, updated after every US close, with the exact prices to act at.
BIIB has a current end-of-day Hesper Atlas signal, refreshed after every US close. It is not real-time. The latest state and the full trade plan (exact buy / add / trim / sell prices) are in the app; a free account shows three full stock pages a day, no card required.
On the later 40% chronological validation tail, originally withheld from early tuning but reused in later research, the BIIB engine returned +11.3% a year versus +2.8% buying and holding, with a worst drop of −26.5% versus −76.2% (after costs, next-day fills, 2026-07-07 evaluation).
The public historical replay contains 4 closed BIIB replay signals (1 ended in profit), regenerated nightly with today’s rules from end-of-day data, losers included.
What the engine did on BIIB, honestly
Closed replay signals on BIIB
| Entry | Price | Exit | Price | Return | Days |
|---|---|---|---|---|---|
| 2025-08-21 | $139.12 | 2026-05-28 | $196.39 | +41.2% | 280 |
| 2023-04-03 | $277.34 | 2023-07-20 | $274.70 | −1% | 108 |
| 2022-10-26 | $280.43 | 2023-02-27 | $269.20 | −4% | 124 |
| 2022-09-30 | $267.00 | 2022-10-03 | $264.30 | −1% | 3 |
All 4 closed BIIB round trips today’s engine produces in the replay window, winners and losers, newest first.
Validation numbers: the engine is tuned on the earlier 60% of this name's history and scored on the later 40%, after costs with next-day fills. That tail was originally withheld but reused in later research, so it is not a pristine unseen test. Backtested, not live. Replay rows are BUY-to-SELL round trips regenerated nightly from end-of-day data; losers stay listed. Method on the methodology page; the row-level artifact is in validation JSON; every name’s current-rule replay slice is on the historical replay page. Hesper Atlas is an educational publication with one systematic signal per name, identical for everyone. It is not financial advice and does not know your situation.
More names in Genomics & AI-Health
Each carries the same daily buy / hold / sell signal. All 155 tracked names are on the stocks index, grouped by theme.