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How Biotech Stocks Move Around FDA Decisions
Original data from 70 PDUFA decisions BioRadar tracked between May 2025 and Sep 2026. Updated automatically as new FDA decisions are archived.
Across 65 FDA decision dates with price data, biotech stocks moved an average of -1.7% on the decision day and -4.3% over the following five trading days. Stocks rose an average of +2.8% in the 30 days before the decision, then 51% closed lower on the day itself — the classic "run-up then fade" pattern. The average absolute move was 9.0%, and single events ranged from +41.5% to -70.7%.
Distribution of decision-day moves
Most FDA decision days are quieter than headlines suggest — but the tails are brutal. Of 65 events:
58% of decisions landed within ±5%, yet roughly 1 in 9 events moved more than 20% in one direction. FDA decisions are high-variance, not one-directional.
The run-up then fade pattern
On average, biotech stocks in this dataset climbed +2.8% in the 30 days before their PDUFA date (60% rose during the run-up window), then gave back ground: -1.7% on the decision day and -4.3% five days later. In other words, the anticipation was often rewarded more reliably than the event itself.
Learn the terms behind these numbers: PDUFA date, Complete Response Letter, full glossary.
By application type
| Application type | Events | Avg 30d run-up | Avg decision-day move | % closed up |
|---|---|---|---|---|
| NDA | 40 | +3.4% | -1.1% | 50% |
| BLA | 16 | +7.2% | -4.1% | 44% |
| sNDA | 8 | -2.6% | -0.6% | 50% |
NDA = New Drug Application (small molecules) • BLA = Biologics License Application • sNDA = supplemental NDA (label expansions).
Approved vs. rejected: what the decision did to the stock
Of 36 verified FDA decisions in this dataset, 23 were approvals and 13 were Complete Response Letters, an approval rate of 64%. Approved stocks moved an average of -0.1% on the decision day; stocks that received a CRL moved -13.7%.
| Outcome | Events | Avg 30d run-up | Avg decision-day move | Avg 5-day move |
|---|---|---|---|---|
| Approved | 23 | +15.6% | -0.1% | +0.9% |
| CRL | 13 | -14.7% | -13.7% | -33.1% |
Outcomes are verified against openFDA or a dated headline that explicitly reports the FDA action; unverified events are excluded from this table. Small samples: treat the averages as indicative, not predictive. See each verified decision →
What this means for traders
- The pre-decision run-up was, on average, more reliable than the decision-day move. Many traders take risk off before the binary event for this reason.
- Most decision days are quiet, but position sizing matters because the tails (±20%+) are severe and hard to predict.
- Averages hide the binary nature of each event — a single approval or CRL can gap a stock 40%+ either way.
Know which FDA decisions are coming — and their approval odds
BioRadar tracks every upcoming PDUFA date with a Probability of Approval score, cash-runway and dilution risk, and free email alerts. Position before the run-up, not after.
See the PDUFA Calendar →Methodology
These statistics are computed from 70 historical PDUFA (FDA decision) events tracked by BioRadar between May 2025 and September 2026. Price reactions use Yahoo Finance daily closes: the 30-day run-up compares the close ~30 calendar days before the event to the close the day before; the decision-day move compares the first close on or after the event to the prior close; the 5-day move extends that to five trading days later. Events are drawn from SEC and FDA filings. Decision outcomes (approved, CRL) are verified against openFDA or dated headlines that explicitly report the FDA action; price action is never used to infer an outcome. Figures update automatically as new decisions are archived. This is informational only, not investment advice.
Last updated: September 18, 2026 • Browse the full historical outcomes table →