PDUFA Date Trading Strategy: How to Trade FDA Decisions

Trading around PDUFA dates is one of the most popular — and most dangerous — strategies in biotech. An FDA decision is close to a binary event: approval can send a stock up sharply, while a Complete Response Letter can gap it down 40% or more. This article outlines how traders think about these events. It is educational, not investment advice.

The run-up trade

Biotech stocks often rise in the weeks before a PDUFA date as traders position for a positive outcome. In BioRadar’s data on how biotech stocks move around FDA decisions, stocks rose an average in the 30 days before the decision, and the pre-event run-up was, on average, more reliable than the decision-day move itself. Many traders therefore focus on the anticipation phase rather than holding through the binary event.

The run-up trade means buying into strength ahead of the catalyst and reducing or exiting before the decision — taking the speculative move without the binary risk. The timing of events and volume trends help identify when a run-up may be underway.

Holding through the event

Holding into the decision is a true binary bet. The upside on approval can be large, but the downside on a CRL is severe and immediate. Traders who hold through typically size positions small enough to survive a worst-case gap, and they decide in advance what they will do on each outcome. Averages hide this: a single event can move a stock far more than the typical case.

Position sizing and risk

Because outcomes are extreme, position sizing matters more than direction. Our distribution data shows most decision days land within a modest range, but the tails are brutal — a meaningful share of events move more than 20% in one direction. A position that is comfortable on an average day can be ruinous on a tail day. Options are sometimes used to define risk, but implied volatility is usually elevated into the event, so premiums are expensive.

What raises or lowers the odds

Before an event, traders weigh:

• Was the pivotal trial clearly positive on a meaningful endpoint (mOS, PFS/OS) with a strong hazard ratio?
• Was there an advisory committee, and how did it vote?
• Any safety signals, manufacturing concerns or prior CRLs?
• Is the company well-funded, or could it need to raise capital and add dilution?

BioRadar assigns each upcoming decision a Probability-of-Approval score with its reasoning shown, which is one input into this analysis.

Common mistakes

• Confusing a delayed readout with good news. In a blinded trial, delayed events can come from the control arm, not the drug.
• Oversizing the binary bet. The tail risk is the whole story.
• Ignoring dilution. Even an approval can disappoint if the company must raise capital to launch.
• Chasing after the move. The reliable part of the trade is often the run-up, not the reaction.

Frequently asked questions

Should you hold a biotech stock through its PDUFA date?

Holding through a PDUFA date is a binary bet with large upside on approval and severe downside on a Complete Response Letter. Historically the pre-event run-up has been more reliable than the decision-day move, which is why many traders reduce exposure before the event. Anyone holding through typically sizes the position to survive a worst-case gap. This is educational information, not investment advice.

Do biotech stocks always go up before an FDA decision?

Not always, but on average biotech stocks have tended to rise in the weeks before a PDUFA date as traders position for a positive outcome. The effect is an average across many events — individual stocks can fall into a decision, and a strong run-up is not a prediction of approval.

What is the biggest risk trading FDA decisions?

Tail risk. While many decision days are relatively contained, a Complete Response Letter or a surprise safety issue can gap a stock down 40% or more in a single session. Position sizing that survives the worst case matters more than being right about the direction.