When US president Donald Trump launched his own meme cryptocurrency on January 17, days before his return to the White House, I was halfway up a Swiss alp, attending a crypto conference in the town of St. Moritz.

Memecoins, which typically have no purpose beyond financial speculation, were having a moment. The previous year, millions of new memecoins had flooded the market; a few, like Fartcoin, had rocketed to billion-dollar valuations. Pump.Fun, a platform for launching and trading memecoins, had become one of the fastest-growing crypto launchpad businesses ever. Now, the soon-to-be president was getting in on the act.

Over lunch on the second day of the conference, beneath the ornate stucco ceiling and golden chandeliers of the…