Trading Sessions for U.S. NMS Stocks

What are NMS stocks? 
NMS stocks are U.S. securities listed on major exchanges like NYSE and Nasdaq, and are covered by the National Market System (NMS). They are regulated by SEC rules to ensure fair and transparent trading. Regardless of which exchange an order is submitted to, investors receive the best available bid and offer prices at that moment across all exchanges (National Best Bid and Offer, NBBO).

Trading Sessions for U.S. NMS Stocks
When trading U.S. NMS stocks, you can choose the session during which your order will be active. Orders will only attempt to execute within the selected session.
You may select from three session options:

• Overnight: Orders are active outside standard market hours.
• RTH + Pre/Post-Market: Includes Pre-Market, Regular Trading Hours (RTH), and Post-Market sessions.
• Regular Trading Hours (RTH): Orders are active only during standard market hours.

Note：

• (+1) means the session ends on the next day.
• "Full Day" and "Half Day" refer to standard and shortened trading days respectively.
• Order Expiration: Orders that are not filled by the end of their selected trading session will automatically expire. For example:  An order placed for the "Overnight" session will expire if it remains unfilled at the end of that session.
• Availability: Session selection is currently available only for qualified NMS (National Market System) stocks. Sahm may adjust the list of qualified stocks from time to time as circumstances require. Any such changes will be made without prior notice.