A Market or a Stop order is only active during the Regular Trading Hours after the "OP" opening print on the primary Listing exchange. IBKR only allows Limit and Stop Limit order types to be active that are configured to work in the Pre-Market and After-Market trading hour sessions for US Stocks. Market and Stop orders for US Stocks will only work during the US Regular Trading Hours of (09:30 - 16:00 EST).
If you wish for your Limit and Stop Limit orders for US Stocks to work “Outside of Regular Trading Hours” (During 04:00 to 09:30 and 09:30 to 16:00 and 16:00 to 20:00 EST) please reconfigure the TWS to allow triggering and routing to “Allow Outside Regular Trading Hours”. Please note that if you select “Allow Pre-Open” then only a “Limit” order type will be active staring at 04:00 EST. A Stop Limit order with “Allow Pre-Open” will not start working until 09:30 EST.
You can define this setting from the Timing section of the Order Preset for a specific asset type, or on a per-order basis from the Time in Force field checkbox "Fill outside RTH.". If outside regular trading hours is not available for the specific order you are submitting, you will not be allowed to populate the checkbox.
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