A limit on close order only executes if the price of the asset is at or below the limit price when the market closes. These orders can also be partially filled, using the limit price as the ceiling for the order. For example, if a limit on close order is placed for Tesla shares at $600 it will only activate if Tesla is at or below $600 at the close. If the limit on close order is for 1,000 shares and Tesla closes at $590 it is possible the whole order could be filled at $590, but the trader might also see 500 shares purchased at $590 and the other 500 shares purchased at $595.