Key characteristics of a market order include:

1. Immediate Execution: The primary advantage of a market order is speed. It’s designed to be executed as quickly as possible, making it ideal for investors who want to enter or exit a position without delay.
2. No Price Guarantee: While a market order guarantees that the trade will be executed, it does not guarantee the price at which it will be executed. The final price may differ from the last quoted price, especially in fast-moving or volatile markets.
3. Best Available Price: A market order will fill at the best available price in the market at the time of execution. For a buy order, this means it will be executed at the lowest available ask price. For a sell order, it will be executed at the highest available bid price.
4. Liquidity Dependence: The execution of a market order depends on the availability of buyers and sellers in the market. In highly liquid markets, market orders are generally filled quickly and close to the expected price. However, in less liquid markets, or for large orders, the price may vary significantly.
5. Use Cases: Market orders are commonly used by investors who prioritize the execution of the trade over the price, such as when they need to buy or sell a security quickly or when the security is highly liquid with minimal price fluctuation.

In summary, a market order is a straightforward and efficient way to buy or sell a security at the current market price, though it comes with the risk of price slippage in volatile or illiquid markets.