Shares of Upstart have been extremely volatile since the company went public in 2020. The stock zoomed from $20 to almost $400 in the first year before cratering back toward its IPO price as its revenue tumbled and profitability dried up. That volatility will likely keep many investors away from Upstart stock.However, the company's AI-powered lending platform holds tremendous promise. As more lenders use the platform to approve loans, it could drive Upstart's revenue and profits skyward. That could also give its stock a jumpstart to start rising again. Investors with a high risk tolerance and seeking a high upside opportunity should consider buying Upstart stock.