Donald Trump has united some of his supporters and detractors in buying shares in his new company and hoping to score a big win. Anthony Nguyen, a 49-year-old software consultant from Austin, Texas, is a Republican who refused to vote for the former U.S. president in last year's election. Last week he joined the millions of online day traders who drove up the value of the company that will house Trump's new social media venture to almost $12 billion. The company's app has yet to be rolled out even on a trial basis, and Nguyen said he invested because he...