In early 2021, millions of ordinary people across the United States began buying shares of the declining video game store GameStop in increments of tens, hundreds or thousands of dollars. Their investments were mocked by financial experts, who cited the store’s poor underlying metrics. But the masses’ collective action proved shockingly powerful: they pushed GameStop’s price from under $3 to as high as $483 in late January 2021, causing the hedge funds that had bet against it to lose billions of dollars.

Nearly three years later, the new movie Dumb Money attempts to dramatize and make sense of the strange episode. Paul Dano stars as Keith Gill, a trader and livestreamer whose full-throated support of the stock on the subreddit community Wall Street Bets catalyzed a movement around “meme stocks”: assets that surged in price fueled by social media enthusiasm. Seth Rogen, Pete Davidson and America Ferrera all play various characters swept up in the mania that …