Initial public offerings (IPOs) & Direct Listings (DLP) are a company's first sale of stock to the public.
How It Works
You can place pending orders once there's an estimated price, however, market orders will not be accepted until the company begins officially trading publicly, once that happens, orders will get filled in a regular fashion.
When to Expect Order Execution
Most often, stocks don't begin trading at market open on the day of their IPO/DLP. Regular trading usually begins 2-3 hours after the opening bell, so you may not have your order filled until later in the day. However, don't be alarmed as this is completely normal & it's how all such events work.