What happened Shares of Vaxart (NASDAQ: VXRT) rocketed 40% higher on Tuesday, furthering the biotech company's sharp ascent in recent days. So what On Monday, Vaxart's stock skyrocketed 52%, following bullish comments by B. Riley FBR analyst Mayank Mamtani. Mamtani began coverage of Vaxart and placed a buy rating and a $22 target price on its shares. Even after today's gains, his new price forecast represents a potential return of roughly 30%, based on Vaxart's current stock price of $16.97. Vaxart's stock surged on Tuesday. Image source: Getty Images. Mamtani highlighted Vaxart's ability to produce a "broad pipeline" of potential vaccines from its cutting-edge oral vaccine platform. He's particularly intrigued by the prospects of the company's oral COVID-19 vaccine candidate, and he expects clinical studies to prove the effectiveness of Vaxart's approach. Now what Investors are bidding up the shares of innovative companies with strong coronavirus-related growth prospects. Vaxart certainly fits that criteria, and its stock price has reacted in kind. However, while Vaxart's experimental COVID-19 vaccine does have exciting potential -- not only for investors, but for people all around the world -- it has not yet proven to be both safe and effective. Moreover, Vaxart has formidable competition in the race for a COVID-19 vaccine, including healthcare titans Pfizer, Johnson & Johnson, AstraZeneca, and more than 100 other companies. Investors, therefore, should view Vaxart as a relatively high-risk stock -- and size their positions accordingly. 10 stocks we like better than Vaxart, IncWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Vaxart, Inc wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 2, 2020 Joe Tenebruso has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source