Merck (MRK) Stock Update: This Week’s News, Key Catalysts, and the Week-Ahead Outlook (Updated Dec. 12, 2025)
Merck & Co., Inc. (NYSE: MRK) ended Friday, December 12, 2025, at $100.30, climbing 1.30% on the day and finishing slightly higher for the week after a choppy stretch driven by vaccine-policy headlines and scrutiny around RSV preventive therapies. StockAnalysis Below is a detailed, Google News/Discover–ready look at what moved Merck stock this week, what the latest company and sector…