A large block of shares that can be sliced by dividing it into smaller lots (known as the child orders) in execution of a transaction. A parent order is typically used in many algorithmic trading strategies to structure a trade. For example, a time-weighted average price (TWAP) algorithm may be used to slice up the parent order for 100,000 shares into 10 child orders of 10,000 shares each, executed with specified time intervals over the course of several hours or days. However, a volume-weighted average price (VWAP) algorithm would divide the parent order into child orders with varying sizes based on the historical average volume of trading of shares at a given time.