On April 7, 2025, the S&P 500 experienced its largest intraday swing since the 2010 flash crash, with a notable 7% fluctuation. The Nasdaq-100 (QQQ) saw a 9% intraday swing, while the E-mini S&P 500 futures ($ES_F) recorded an 8% swing during regular trading hours. The volatility was underscored by the S&P 500's movement from a peak increase of 4% to a closing decline of over 1%, marking the first occurrence of such a swing since at least 1978, according to market analysts. Ryan Detrick highlighted that this unprecedented movement had not been recorded in historical intraday data extending back to 1978.