The largest US stock exchanges plan to soon have a common procedure for reopening trading after a halt.

Nearly a year after a wild trading session on August 24, 2015, led to more than 1,000 stock and exchange-traded fund halts in a single day, NYSE Group, a unit of Intercontinental Exchange, Nasdaq and Bats Global Markets outlined a series of planned measures on August 11 aimed at smoothing trading activity. Among the moves will be a unified process by which stocks and ETFs resume trading after a halt.