Merck’s stock tumbled 11.8% on Tuesday, its biggest one-day selloff in almost 17 years, due to weaker-than-expected guidance and struggles with its HPV vaccine in China. The company’s quarterly earnings beat was overshadowed by the disappointing news.
This decline is similar to a previous drop in March 2008, when Merck’s stock fell 14.7%. The current slump has pushed the stock to two-year lows, making it the second-biggest decliner among S&P 500 companies.
Source: https://www.marketwatch.com/story/mercks-soft-guidance-offsets-better-than-expected-fourth-quarter-earnings-7f2d6f4a