https://www.reuters.com/article/us-facebook-privacy-zuckerberg/facebook-shares-rise-sharply-as-zuckerberg-deters-regulation-talk-idUSKBN1HH1CU >Facebook Inc shares posted their biggest daily gain in nearly two years on Tuesday as Chief Executive Mark Zuckerberg fended off questions from U.S. senators on how the world's largest social network might be regulated more closely.