Rivian Automotive (RIVN) shares plunged 5.09% during the intraday session following a downgrade by UBS from "Neutral" to "Sell." The bank raised its price target to $15 from $13 but cited elevated expectations and overvaluation as key risks.

UBS analysts noted that the market's enthusiasm for Rivian's AI and self-driving initiatives may have peaked after a 15% rally since December 11. They also expressed skepticism about the company's ability to meet Wall Street's high expectations for its upcoming R2 model sales.

Despite recent gains, Rivian faces growing skepticism, with only 30% of analysts rating the stock a "Buy." The downgrade reflects broader concerns about the stock's valuation after its rapid ascent in recent months.