
Late in 2025, shares in Snap (SNAP) surged as much as 25% following the company's announcement that it had signed a deal to integrate an answer engine powered by artificial intelligence into its social-media app Snapchat. A day later, Duolingo (DUOL) stock plunged 25% after the language-learning platform lowered its guidance for earnings for the quarter ahead.
Both price moves occurred after the traditional stock-exchange hours of 9:30 am to 4 pm Eastern Standard Time. Opportunistic investors who traded after the market closed were able to limit their losses in Duolingo stock or pocket a nice gain in Snap shares.