Former President Donald J. Trump’s stake in his social media company is worth half of what it was before his conviction on charges of falsifying business records to cover up a sex scandal during the 2016 presidential campaign Mr. Trump’s roughly 65 percent stake in Trump Media & Technology Group, the parent of Truth Social, was worth roughly $6 billion on May 30, the day a New York jury found him guilty on all 34 charges. On Friday, the value of his 115 million shares of Trump Media...