A market order is an order to immediately buy or sell a security at the best available current price. It is the fastest way to execute a trade, as it prioritizes execution speed over a specific price.
When you place a market order, your broker immediately sends it to the exchange. The order is then filled at the best available bid (for a sell order) or ask (for a buy order) price from the market makers and other participants.
Suppose you want to buy 100 shares of Company XYZ.
If you place a market order to buy 100 shares:
Your order will first look at the lowest available ask price, which is $50.05.
Since there are 200 shares offered at $50.05, your entire order of 100 shares will be filled at this price.
If you placed a market order to buy 250 shares:
Your order would first fill 200 shares at $50.05.
The remaining 50 shares would then be filled at the next lowest ask price, which is $50.10.
In this scenario, your average purchase price would be: ((200 shares * $50.05) + (50 shares * $50.10)) / 250 shares = $50.06.