https://www.reuters.com/article/us-robinhood-stocks/meme-stock-robinhood-jumps-10-in-end-to-turbulent-week-idUSKBN2F71IE >(Reuters) -Shares of Robinhood Markets Inc rallied 10% on Friday after a roller-coaster week that has made the online brokerage among the hottest of so-called "meme" stock and added $18 billion to its value.