I guess they say it was the biggest day in financial history,” President Donald Trump told reporters Wednesday afternoon.

The game's emphasis is on learning – from both mistakes and successes – about the markets through real-time market simulation. The platform offers both individual and competitive play.

Later, in an apparent hot-mic moment, he told a fawning senator that the market was up almost seven percentage points. “Nobody’s ever heard of it. It’s gonna be a record.” It was a ...