Prediction markets have priced the Trump-Xi summit. Do the bets have any value?

US President Donald Trump has already announced the date: September 24. That is when, Trump says, Chinese President Xi Jinping will come to the White House for a visit following the “America first” leader’s own three-day trip to Beijing in May. But there is a diplomatic wrinkle. The Trump administration has publicly put the date on the calendar. Beijing has not formally announced Xi’s Washington visit. According to sources familiar with the plan, Xi is expected to arrive in Washington on...