Movers & Shakers: Prometheus Biosciences, XPeng, Alphabet, Roblox and other stocks on the move Monda

Getty ImagesHere are some of the biggest movers on Monday:Stock gainers:Prometheus Biosciences Inc.’s RXDX stock was skyrocketing nearly 70% after drug maker Merck & Co. Inc.MRKsigned a deal on Sunday to acquire the biotech company for $200 a share, or about $10.8 billion. Merck shares were down 0.4%.U.S.-listed shares of electric-vehicle maker XPeng Inc. XPEV were up over 13% in afternoon action after the company released a new production platform that it says will cut the research and...