How far biotech stocks tend to move on, and into, an FDA decision — by company-size tier, across 694 decisions in our cohort. Historical base rates, not predictions.
Median decision-day move (absolute)
The decision-day reaction falls cleanly with size: a micro-cap typically swings ~7× more than a large-cap on the day. This is the most consistent pattern in the dataset.
Median T-120 run-up into the date
Honest caveat: the pre-decision run-up is far noisier than the decision-day move and does not fall perfectly by size — here mid-caps run up more than small-caps. Run-up reflects many things (pipeline news, dilution, sector moves), so treat these as rough central tendencies, not a ladder.
Source: pdufa.bio internal cohort of 694 FDA decisions (2024–26) with complete price data, decision-day and trailing-120-day. Figures are medians of absolute moves; individual events vary widely. Not a prediction for any specific drug. Method: methodology · sources.