Trader Brian Jones on Twitter: "Stock sales tied to a hedge fund’s unwinding fueled a 27% plunge Friday in shares of Viacom—an unusually large decline on a day with no significant company-specific news https://t.co/5NXdC8ytMt via @WSJ" / Twitter

Stock sales tied to a hedge fund’s unwinding fueled a 27% plunge Friday in shares of Viacom—an unusually large decline on a day with no significant company-specific news wsj.com/articles/ex-ti via