JPMorgan Chase & Co. Chief Executive Officer Jamie Dimon said he would fire any employee trading bitcoin for being “stupid.”

The cryptocurrency “won’t end well,” he told an investor conference in New York today, predicting it will eventually blow up. “It’s a fraud” and “worse than tulip bulbs.”

Bitcoin has soared in recent months, spurred by optimism that faster transaction times will hasten the spread of the cryptocurrency — a run that has drawn debate over whether it’s a bubble. Bitcoin’s price fell after Dimon’s remarks.

Tulip mania swept Holland in the 17th century, with speculators driving up prices of virtually worthless tulip bulbs to exorbitant levels. That didn’t end well.