Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why ever use a market order?
The original poster's concern is valid.  Sometimes, market orders do get executed at seemingly ridiculous prices. In addition to Victor's reasons for using a market order, sometimes a seller does not care how low the price is.  For example, after a company goes broke, its stock continues to trade for a while.  This allows shareholders to realize their losses for tax purposes, and allows short-sellers to close out their positions.  A shareholder who is trying to realize a 10 dollar per share loss for tax purposes probably does not care whether he gets 10 cents per share or 0.001 cents per share, so a sell-at-market order makes sense.