Quote from forex-forex:
With all the work of studying a stock why risk not getting filled with a limit order?
Why risk getting filled at a bad price with a market order?
With a limit order you specify the maximum you want to pay, or the minimum you want to receive. That means you can't get ripped off, because you will never get a fill at a worse price than your limit. Therefore, market orders are only useful if you want a fill at a worse price than your limit, which you never do - because that's your limit.
Only crazy people place an order of "give me one of those - at any price" (market). Normal people say "give me one of those - but if it's too expensive, forget it" (limit).
