What Happened? Shares of language-learning app Duolingo (NASDAQ:DUOL) fell 27.4% in the morning session after the company's weaker-than-expected profit forecast for the fourth quarter overshadowed its strong third-quarter results. The language-learning app posted impressive third-quarter numbers, with revenue of $271.7 million and earnings of$5.95 per share, significantly beating Wall Street's estimates. However, the positive results were undone by the company's outlook. While Duolingo's fourth-quarter r ...