The New York Stock Exchange and the NASDAQ operate from Monday - Friday, between the hours of 9:30am - 4:00pm EST.
Purchase or sale orders made outside of Market Hours, will not be fulfilled until the Market reopens.
Placing an order outside of Market Hours will result in a 'Pending Order'. If you attempt to repeat an order that is already pending, you will receive an error.
How to View Pending Orders*
Navigate to the Portfolio tab of the MyWallSt app.
Tap Brokerage (in the top right-hand corner).
Choose Pending Orders.