Long position (buy order): A long position is taken when an investor expects the price to rise. It is opened at the ask price and closed at the bid price. You make a profit when the bid price is higher than your opening price.

Short position (sell order): A short position is taken when an investor expects the price to fall. It is opened at the bid price and closed at the ask price. You make a profit when the ask price is lower than your opening price.