The closing price is the final price at which a security trades during a regular trading session. This price serves as an important reference point for calculating daily returns, determining option exercise decisions, and settling various financial contracts. Closing prices are used in technical analysis, performance measurement, and many automated trading systems.

Different markets use various methods to determine closing prices, including the last trade price, volume-weighted average of final minutes, or special closing auctions. The closing price often influences after-hours trading and next-day opening prices. Many derivative contracts and index calculations rely on official closing prices for settlement and valuation purposes.

Real-world example: Apple stock’s closing price of $175.50 on Friday determines weekend option expiration outcomes and serves as the starting reference point for Monday’s opening gap calculations.