TuSimple filed the first of four late financial documents this week. It’s easy to see why the autonomous truck software developer gave up freight hauling. It cost more than twice as much as it was seeing in revenue. And the company has just 250 U.S. employees after two rounds of layoffs and a refocus on Asian markets. While other startups ran afoul of Nasdaq listing rules because their share price fell below $1 for more than 30 consecutive trading days, TuSimple found another way to get put on double-secret probation (to borrow a line from the college fraternity sendup “Animal...