Elon Musk, the Tesla billionaire who has become a close advisor to U.S. president-elect Donald Trump, surprised people with an unexpected crypto endorsement this week. Now, as traders bet that Trump will follow through with an outlandish plan to create a bitcoin strategic reserve and wipe out the U.

Musk’s concerns over the U.S.'s escalating $35 trillion debt coincide with a surge in bitcoin’s value, outpaced by the rapid rise of dogecoin, a meme-based bitcoin competitor that has gained traction with Musk’s support for the Department of Government Efficiency, known as Doge.

Dogecoin was once a joke, but the meme coin gained traction after Elon Musk backed it. Now he's set to co-lead a D.O.G.E. government agency. Here's a look back.