All trade orders, buy and sell, are executed at the close of the stock market. This is 4 PM ET*.
If your trade is entered into your Stockpile account after 3 PM ET on a market/business day, your order will execute at 4 PM on the next business day.
For sell trades, the cash will settle in your account on the first business day following the day that your order executes. If you would like to learn more about T+1 settlement time, click here.
If you sell a stock, the cash from the sale will appear in your Stockpile account the next business day. You can then use that cash to buy more stock. However, keep in mind that your purchase order will execute at the end-of-day using the closing price. For example, if you place a sell order on Monday at 8 a.m., the the order will execute at 4 pm ET and the proceeds from the sale will be available for trading the next business day. If you place an order to buy before 3 pm ET, then your order will execute at 4 p.m. on Tuesday.
*The cut-off time is a little earlier if the market is closing early, for example, the day after Thanksgiving or Christmas Eve. If you would like to see the Market Calendar & Trading Hours, please click here.