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What happens to a stock on its PDUFA date?
A PDUFA decision is a binary catalyst: the FDA either approves the drug, issues a Complete Response Letter (CRL), or extends the date. The stock reaction is usually sharp — and historically its size scales inversely with company size.
Decision-day move by company size (history)
Micro-cap (<$300M)~±7% median
Small-cap ($300M–$2B)~±3%
Mid-cap ($2B–$10B)~±2%
Large-cap (>$10B)~±1%
Those are median absolute moves across a 694-PDUFA cohort (2024–26) — the typical reaction, not a prediction for any one drug. Individual binary events can move a micro-cap 50%+ in either direction. There's also often a run-up into the date that fades near the decision; see our run-up-by-market-cap study.
Why size matters
A single approval can be the entire thesis for a one-drug micro-cap, but a rounding error for a diversified large-cap. That's why the same news moves them so differently. Related: how often the FDA approves drugs.
How much does a biotech stock move on its PDUFA date?
Historically the median decision-day move scales with size: about ±7% for micro-caps, ±3% small, ±2% mid, ±1% large (694-PDUFA cohort, 2024-26). Individual events can be far larger. These are historical base rates, not predictions.
Do biotech stocks run up before a PDUFA date?
Often, yes — there's frequently a run-up into the date that tends to fade near the decision, but it varies widely and is not guaranteed.