The meme stock era, led by Keith Gill, aka “Roaring Kitty,” seemed to have come and gone — until this week, when he reemerged on social media. It was enough to send shares in GameStop and AMC on a wild ride again, conjuring memories of 2021’s meme stock mania.

So what’s really going on? On today’s episode, Bloomberg’s Money Stuff columnist Matt Levine schools us in Meme Financial Markets — and breaks down for host David Gura what these wild moves mean for anyone interested in putting money in the stock market.

Read more: GameStop Is Back!?