A method and apparatus is described for performing transaction tracing. The method may include mapping one or more funds flow transactions into each account to one or more funds flow transactions out of said each account based on a first-in-first-out ordering. The method may also include generating an initial graph from the mappings of the transactions for each said account. Furthermore, the method may include transforming the initial graph to a function graph, wherein the functional graph is a directed pseudoforest where each node has an out degree of at most one. Then, the method may include for a node in the functional graph, performing a trace of the transaction generating a set of transactions that contributed to the transaction.