Shares of Merck MRK.N slipped 9.0%. The Labor Department's report showed U.S. employment increased more than expected last month as COVID-19 infections over the summer subsided, offering more evidence that economic activity was regaining momentum early in the fourth quarter. A stellar third-quarter reporting season, coupled with cheery outlook on earnings growth as well as a central bank in no rush to hike interest rates, has boosted investor appetite for equities, helping them look past worries about inflation, supply chain disruptions and labor shortages.