Everybody and their mamas are into bitcoin and cryptocurrencies nowadays, but John Oliver and Keegan-Michael Key want you to know what the heck you’re doing before you invest.

Oliver’s show, Last Week Tonight, recently dedicated an episode to technology, or as he called it “the thing that will make television so high def that I will no longer be allowed to appear on it.”

Inevitably, the bitcoin trend came up, and Oliver was less than enthusiastic about cryptocurrency. He said it combines “everything you don’t understand about money … with everything you don’t understand about computers.”

The media has been reporting on bitcoin for a while, and because the science behind blockchains can very quickly get complicated and boring, Oliver brought on Keegan-Michael Key for a hilarious sketch meant to help all of us get a better handle on the future of money.

The comedian mocked a cryptocurrency investor at a conference that claimed investing in crypto would “change the world as we know it” in the middle of otherwise unintelligible yelling about “bitconneeeect.”

Key took the opposite approach and warned people to be “craeful” when investing in Bitcoin or any other cryptocurrency.

“The crypto market is extremely volatile and insufficiently regulated,” Key yelled. “They pump and dump!”

“Investing in cypto could be like getting in on Google on the ground floor,” Key added, before tempering that with, “Or, it could be like getting in on Google Glass on the ground floor, and that turned out to be a one story building!”

Think of Key’s message before you let your homeboy convince you to invest your rent money into bitcoin.