If your brokerage charges trading fees, a single limit order should incur the same fees as a market order. Fees on limit orders can add up, though, if the trade is executed as more than one order. Say, for example, you want to sell 1,000 shares of X at or above $5. When the price of X reaches $5, your order is sent to be executed, but there aren’t many buyers and only half of your order is executed before the price drops back below $5. The next time the $5 threshold is reached, the remainder of your order is executed, but you’ve been charged for two trades. You can avoid this scenario with “all or none” or “fill or kill” orders, but then you run the risk of the order not executing at all.