‘Dumb Money’ Is on GameStop, and It’s Beating Wall Street at Its Own Game

A real estate salesman in Valparaiso, Ind. A former line cook from the Bronx. An evangelical pastor and his wife in Huntington Beach, Calif. A high school student in the Milwaukee suburbs.

They are among the millions of amateur traders collectively taking on some of Wall Street’s most sophisticated investors — and, for the moment at least, winning. Propelled by a mix of greed and boredom, gleefully determined to teach Wall Street a lesson, and turbocharged by an endless flow of get-rich-quick hype and ideas delivered via social media, these investors have piled into trades around several companies, pushing their stock prices to stratospheric levels.