The extreme volatility in the first few weeks of the coronavirus crash was too much for some trading platforms to handle. But the major U.S. stock exchanges themselves have functioned as normal -- even as they closed their trading floors and began remote operations like most of the financial world. There are some good reasons why.
The Great Recession led to several reforms to help markets operate more efficiently and, in particular, mitigate the incidence of flash crashes. The most notable flash crash occurred on March 6, 2010, when the market lost 9% of its value in a matter of minutes, only to mostly recover within the hour. Flash crashes occur for a variety of reasons and are often exacerbated by high-speed computer trading platforms that rely on algorithms. When there is a glitch in the program or the algorithms recognize certain aberrations, it can lead to an extreme spike in trades.