Most stocks, though, can be traded before or after those hours. It's puzzling for some investors that there's no similar premarket and after-hours trading available for many stock options. How to Buy Stock When the Market Is Closed. Just because the stock markets close at 4 pm does not mean that trading stops. Thanks to the ECN, or Electronic Communication Networks, you can still Same strategies as securities options, more hours to trade. Cash-secured puts (cash on deposit to buy stock if assigned) Important note: You can also view the E*TRADE Futures LLC Financial Information and Disclosure Documents.