You may choose the validity period of your order to be either GTD (Good 'til Day) or GTC (Good 'til Cancelled). GTD allows you to place a buy or sell order at a particular price and the order will stay active unless fully executed or till the end of the trading day while GTC allows you to place a buy or sell order that will stay active until the price is reached or when you choose to cancel the order. Please note that GTC orders in SGX market automatically expire 30 days after it is placed whereas GTC orders in the US market do not expire.