An open position is any trade that has been established but not yet closed through an offsetting transaction. Open positions create market exposure to price movements and require margin requirements in leveraged trading. These positions remain active until closed through offsetting trades, exercise (for options), or expiration and delivery.

Managing open positions involves monitoring profit/loss, margin requirements, and market conditions that could affect position values. Position sizing, risk management, and timing of position closure significantly impact trading performance. Understanding open position risks and requirements is essential for effective trading and portfolio management.

Real-world example: A trader maintains an open long position of 1,000 shares of Apple stock purchased at $150, creating exposure to price movements that could generate profits above $150 or losses below $150 until the position is closed.