What happened

Shares of Novavax (NVAX -2.26%) were vaulting 9.3% higher as of 3:08 p.m. EDT on Thursday. At first glance, you might think this noteworthy gain stemmed from Novavax's regulatory disclosure after the market closed on Wednesday that the U.K. government agreed to buy 60 million doses of the biotech's COVID-19 vaccine candidate. However, Novavax stock actually fell in the first few hours of trading Thursday morning and only began to rise shortly before 11 a.m. EDT.

The overall stock market rebounded nicely today after big losses earlier this week. This momentum likely helped buoy Novavax. Again though, the major market indexes were climbing in the first few hours of trading while shares of Novavax were sliding.

Perhaps the best explanation behind the solid gain for the biotech stock today is simply that some investors saw an opportunity to buy Novavax at a discount compared to where its shares have traded in recent weeks. This probably created enough upward pressure on a day when trading volume for Novavax was well below its average volume. It's likely that these investors were spurred to some extent by the company's big U.K. deal.

Two rows of vaccine bottles.

Image source: Getty Images.

So what

Investors shouldn't focus on the day-to-day fluctuations for Novavax stock. Instead, the main thing to keep an eye on is the company's opportunity for growth. And that opportunity appears to be better than ever with the U.K. agreeing to buy 60 million doses of Novavax's COVID-19 vaccine candidate.

Novavax didn't disclose the price tag of its supply agreement with the U.K. However, you can bet that it's at least in the upper nine figures and probably more than $1 billion. Without question, Novavax's prospects are now stronger thanks to this deal.

Now what

The key for Novavax now is to show that its experimental coronavirus vaccine is both safe and effective. The company already has a late-stage study in progress in the U.K. in hopes of doing just that. Novavax plans to begin a late-stage study of NVX-CoV2373 in the U.S. by the end of November.