A buy instruction is created when a trade is placed outside of market hours* or during an intra-day auction. Your buy instruction will be converted into a buy trade when the market opens on the next trading day or once the intra-day auction has ended.
If you want to know how to set up a buy instruction, visit this FAQ - How to create a buy instruction?
While you have pending Buy Instructions, the purchase value of those Buy Instructions will be held by us in order to make the purchase when the market is open and will not, therefore, be available as free cash. If you want to access the cash, you will need to cancel the Buy Instructions, which you can do by following these instructions - How do I cancel a buy instruction?
*ZAR trading hours are between 09h10 (09h15 for ETFs) and 16h40 Monday to Friday (excluding public holidays). ZAR trading will be closed on South African public holidays.
*USD trading hours are between 09h30 and 16h00 EST (16h30 and 23h00 local time and 15h30 to 22h00 during US Daylight Savings Time) Monday to Friday. USD trading will be closed on U.S holidays
*AUD trading hours are between 10h15 and 15h50 AEST (02h15 and 07h50 local time) Monday to Friday. AUD trading will be closed on Australian holidays