As such, we could end up with a situation where the US stock markets ends up closing way early for the day because the they tripped all the circuit breakers for an emergency trading stop.
“US stock market authorities have been forced to suspend the futures market on the Nasdaq index.
Panicking traders have driven it down 5% - the maximum allowed under Wall Street rules before a circuit-breaker is triggered.”
http://www.theguardian.com/business/live/2015/aug/24/global-stocks-sell-off-deepens-as-panic-grips-markets-live