The exchange operators said they made the call after consulting with each other, regulators and government officials. They cited concerns about the market's ability to function without disruption and the safety of people who work there.
Nasdaq is shutting the Nasdaq Stock Market and other US Exchanges and markets that it owns. Its exchanges outside the US will operate as scheduled.
CME Group will end trading of equity index futures and equity index options on futures market at 8:15 am Central time.