Why use a Market Order?
XYZ is trading at $250.00 and you would like to purchase the underlying no matter what the price.
1)What to do?
You send a market order to buy XYZ.
Enter the order: Enter a Market order to buy 100 shares of XYZ
2)What Happens Next?
You are executed at the current market price, which could be different than the quote at the time you entered the order.