<p>Systems and methods for reconstructing the state of a market are provided. Orders are arranged as a non-indexed collection of orders and may be stored in the cache memory of a processor. The physical locations of orders stored in the memory may correspond to the order in which they were received at a match engine. A computer device simulates the processing of orders between any time periods to reconstruct the activity state of an entity across a trading platform and one or more order books.</p>
