What happened

Shares of BioNTech (NASDAQ:BNTX) were jumping 10.1% higher as of 11:41 a.m. EDT on Thursday. Neither the German biotech nor its coronavirus vaccine partner Pfizer (NYSE:PFE) announced any news. Today's gain appears to be driven primarily by the overall stock market rise today, which itself was fueled by better-than-expected growth in the U.S. gross domestic product (GDP). It's also possible that many investors thought that the sell-off of BioNTech earlier this week was overdone.

So what

A rising tide really does usually lift all boats. That's pretty much what we're seeing today with BioNTech as the stock market enjoyed a nice bump.

Scientist holding syringe with needle next to a vaccine bottle

Image source: Getty Images.

The more important story for the biotech stock, though, is what happens next with its coronavirus vaccine candidate BNT162b2. Pfizer and BioNTech have consistently predicted that they would know whether or not the experimental vaccine was safe by the end of October.

However, that aggressive timeline now appears to be blown out of the water. Pfizer CEO Albert Bourla said in the company's third-quarter conference call on Tuesday that an interim efficacy analysis for a late-stage study of BNT162b2 still hasn't been performed by the study's independent data monitoring committee.

Now what

Investors will want to be on the lookout for the promised interim efficacy analysis, as it could soon be announced. Assuming those results are encouraging, the next big milestone for BioNTech will come in the third week of November. That's when Pfizer and BioNTech hope to submit for FDA Emergency Use Authorization for BNT162b2.