Teradyne (TER) shares plummeted by 6.39% in pre-market trading on Monday, following a downgrade by Morgan Stanley analyst Shane Brett CFA. The analyst maintained a "Sell" rating on the stock and lowered the price target to $117, citing challenging forecasts and revised revenue and earnings targets as reasons for the bearish stance.

Brett's report suggests that Teradyne is facing headwinds that could impact its financial performance, leading to a potential further decline in the stock price. The analyst's revised outlook and recommendations have raised concerns among investors about the company's future prospects.

The pre-market plunge in Teradyne's shares reflects the market's reaction to the Morgan Stanley analyst's negative report. Investors appear to be pricing in the potential risks and challenges highlighted by the analyst, leading to a significant sell-off in the stock during the pre-market session.