Open has several definitions within investing. It can refer to the daily opening of an exchange, and an order or position that has not yet been filled or closed.
The market open is the beginning of trading on an exchange each day. Market opens vary between exchanges and time differences can be a big factor, The New York Stock Exchange, for example, is open from 2.30pm to 9pm in GMT (assuming the US and UK daylight savings are in sync). The London Stock Exchange is open from 8am to 4.30pm UK time.
We offer out-of-hours trading to allow UK traders to trade US stocks both pre and post-market.
Open orders are orders that have not yet been filled (or executed). The length of time that an order can remain open for, and stipulations involved in filling it, vary between different types of orders. Day orders, for instance, can remain open for a single trading day. Good-‘til-cancelled orders can remain open indefinitely.
An open position is a current position that has not yet been closed.