https://www.reuters.com/article/us-facebook-results-stock/zuckerberg-loses-16-billion-in-record-facebook-fall-idUSKBN1KG1TN >Facebook Inc Chief Executive Officer Mark Zuckerberg's fortune took an almost $16 billion hit on Thursday, as the social media giant headed for the biggest one-day wipeout in U.S. stock market history, a day after executives forecast years of lower profit margins.