Market orders allow you to make trades at the best available current price. A market order is the fastest and more reliable way to get in and out of a trade, and is appropriate if getting filled is more important than getting a specific price.
How is a Market order Filled?
In order to understand how a market order is filled, and what would determine the price, you would need to look at the order book, which is found on the Trade page, beneath the price chart in the advanced view:
Here you will see a list of current Bids (pending buy orders) and Asks (pending sell orders) from other users on the exchange.
What will I pay for a Market Buy?
So, for example, if you are looking to buy bitcoin, you will be trading against sellers (Ask Column). You can view current Ask prices and amounts available by going down the list:
Example: Say you were to enter a Market Buy order for 0.1 BTC, it would be filled by trading against the sellers from the top three rows of the order book, like so:
These three trades will fill your order at the weighted average price of $13,713.00
After the order is filled, your account will be credited 0.09975 BTC (0.1 less the trading fee of 0.25%)
What about Market Sell orders?
Sell Market orders work the same way, except you would calculate your average from the Bids column.
Note: Because of the speed at which trading takes place on our exchange, you may not have the luxury of completing these calculations, since the order book is being constantly updated. Taking a cursory look utilizing the above step should give you an estimate at what price your market order will likely fill at.