Zoetis Is Today’s Worst S&P 500 Stock. Why the Quarter Is ‘Worse Than It Seems.’

Shares of Zoetis plummeted Thursday, after the animal-health company’s results missed Wall Street expectations and cut its full-year guidance. Zoetis stock sank 20% to $88.94 on Thursday, making it the session’s worst performer in the and putting on pace for its lowest close in more than seven years, according to Dow Jones Market Data.