A fill-or-kill (FOK) order is an order to buy or sell crypto immediately at a specified price. If the price is unavailable at the moment, the order is canceled.
With a FOK order, you can get a big amount of crypto right now and for the indicated price. On CEX.IO, you can buy crypto via FOK orders using the Buy/Sell page on the website or in the CEX.IO mobile app. You just need to specify the amount and choose a payment method — your available balance or a payment card.