An execution order (specifically a tick-senstitive order) that triggers the purchase or sale of securities if the market moves down by a tick. Downtick orders come in two broad types: buy downtick orders and sell downtick orders.

Downtick orders constitute traders’ bets or expectations that the trade price will be lower than the last different price (before the tick change). These orders are instrumental for traders who want to buy at lower prices (less than the current ask prices), but they are not available to cancel or re-submit their orders if prices move up.