I use a marketable limit to close long positions at ask+0.05 and have, on 90% of occasions, been able to get a fill at my preferred target. In the 10% of cases I don't, I simply move my limit sell down a bit until it fills and get out at a few cents under my target; but profit is still profit and in these cases, the price continues to push downwards. For short positions i always do a market buy to close. While I can expect 90% of marketable limit buy orders to fill; the 10% that don't could end up in a loss greater than what as planned, particularly if my stop loss is near a critical battleground area such as a MA, VWAP, or previous level. As a risk management strategy, I'm willing to risk a little bit of profit 10% of the time in order to get more optimal fills 90% of the time for long positions; however, for short positions I rather close at less optimal market buys 90% of the time to avoid getting trapped during the start of a bull run 10% of the time- which at least on the type of stocks I primarily trade (small caps with low float), can lead to a trade where my unrealized gains dwindle quickly, and I'm scrambling to place a market buy to close anyways.