The New York stock exchange plummeted significantly at the opening, and at times Nasdaq nosedived to around minus 6 percent. During the day, the indexes recovered somewhat, but still closed a good way below zero.
The industrial index Dow Jones ended the trading day at minus 2.6 percent, while the broad S&P 500 closed at minus 3.0 percent. According to CNBC, Monday was the worst trading day for the two indexes since 2022. At the same time, Nasdaq's composite index fell by 3.4 percent.
The large American technology companies, sometimes called the "magnificent seven", have made significant investments in artificial intelligence and have in several cases seen their shares reach historic highs this summer. The recent days' gains have essentially been erased.
The list of today's losers can be made long. For example, semiconductor giant Nvidia fell by 6.4 percent. At the same time, Apple fell by 4.8 percent and Microsoft by 3.3 percent.
One technology company that went against the trend was processor manufacturer AMD, which increased by 1.8 percent on Monday. Kellanova, which among other things owns the chip brand Pringles, surged by 16.2 percent following rumors of a takeover.
Monday's turbulence is a continuation of last week's downturns, and even several normally defensive stocks have been dragged into the stock market fall, such as food giant Pepsico, minus 2.3 percent, and pharmaceutical company Johnson & Johnson, minus 1.8 percent.