Since its initial public offering in December 2020, Upstart (UPST -2.48%) has been one of the most volatile stocks on the market. It soared out of the gate in 2021 before crashing in the tech-driven bear market of 2022. Over the last year, that volatility has continued, but recently, it's cut against investors. The stock tumbled on its recent earnings report as the artificial intelligence (AI)-based consumer lending company issued disappointing guidance for the first quarter of 2024 with a revenue forecast ...