A Market-to-Limit (MTL) order is submitted as a market order and executes at the current best market price. If the order is only partially filled, the remainder of the order is canceled and re-submitted as a limit order with the limit price equal to the price at which the filled portion of the order executed.

Symbol XYZ shows a bid price of $15.00. You want to buy 500 shares of XYZ at the current best market price. You click the Ask price to create a BUY order, and select MLT in the Type field to specify a market-to-limit order. The word MARKET appears in the Lmt Price field to illustrate that you are willing to buy at the current market price. You submit the order. Immediately 250 shares are filled at 15.03, which is the best market price. The remainder of your order (250 shares) is cancelled and immediately re-submitted as a limit order with the value in the Lmt Price field automatically set to 15.03. If nobody is willing to sell for that price, the remainder of your order will not execute.