A market order is an order to buy or sell a fraction at the market's current best available price. A market order typically ensures an execution, but it does not guarantee a specified price.
Proptee introduced market orders to make it easier for investors to get into or out of an investment.
Market orders are optimal when the primary goal is to execute the trade immediately. A market order is generally appropriate when you think a fraction is priced right, when you are sure you want a fill on your order, or when you want an immediate execution.
In a low liquidity pair, the last trade price may not necessarily be the current price, as the last trade may have occurred minutes or hours ago.
When placing a market order, the current bid and offer prices are generally of greater importance than the last trade price.