What happened

Shares of biotech company Vaxart (NASDAQ:VXRT) rose 12.1% in September, according to data provided by S&P Global Market Intelligence. That sounds good, since the S&P 500 fell 3.9% during the month. But considering its shares were up more than 50% in the first three weeks of September, the company's final performance doesn't seem so impressive. 

Year to date, on the other hand, the start-up's shares have soared nearly 2,000%, an eye-popping number reflecting investors' interest in potential coronavirus vaccines. 

Icons representing viruses, stock price performance, and the globe.

Image source: Getty Images.

So what

The big news for Vaxart came on Sept. 14, when the Food and Drug Administration granted Investigational New Drug clearance to the company's oral coronavirus vaccine candidate. That paves the way to begin phase 1 clinical trials. Shares skyrocketed in response to the news. 

The next day, though, shares dropped, probably as some investors took profits following the stock's incredible run. But when a hot stock pulls back, investors smell opportunity, and on Sept.17, Wall Street was bidding up Vaxart's shares again. By the time the dust settled on Sept. 21, Vaxart was sitting on a 51.5% gain for the month.

However, the next few days saw a series of reports that knocked Vaxart off of its highs. On Sept. 21, The Wall Street Journal pointed out that emergency-use authorization vaccines (which would almost certainly be the status of the first coronavirus vaccines available in the U.S.) aren't covered by Medicare. On Sept. 22, reports surfaced that the FDA might be considering new rules that would delay the authorization of a vaccine. And on Sept. 23, news that biotech heavyweight Johnson & Johnson (NYSE:JNJ) had advanced a single-shot coronavirus vaccine candidate into a pivotal-stage trial weighed on its competitors, including Vaxart. Shares fell, to finish the month up just 12.5%.

Now what

There are so many other potential coronavirus vaccines in phase 3 trials that it's unlikely Vaxart's will be the first (or even one of the first) to market. Bigger companies like Johnson & Johnson have a definite advantage. But because Vaxart's vaccine is taken orally as a tablet, it has huge potential advantages, including easier storage and shipping, and the potential for recipients to self-administer it. 

Although its clearance for phase 1 human trials is a definite plus, Vaxart is still a risky stock, and its valuation has skyrocketed. Only risk-tolerant investors should consider buying, and even they will likely want to invest in multiple coronavirus vaccine hopefuls to help cover their bases.