After placing a Robinhood order, you have an option to revoke it prior to the execution. However, only pending orders can be canceled, and you’ll need to follow certain guidelines regarding the timeframe of the cancelation. More specifically, you shouldn’t submit your request between 9:20 and 9:30 AM Eastern Time. Otherwise, your closure won’t be granted. Additionally, if you try to cancel your regular-hours order for NASDAQ-listed stocks between 9:28 and 9:30 AM Eastern Time, the order will remain pending until the stock’s opening cross takes place. It usually occurs at 9:30 AM Eastern Time. This rule was formulated for NASDAQ stocks and is beyond Robinhood’s control. So, revoke your order before 9:28 AM Eastern Time to prevent an execution.