Abstract: A computer implemented method for determining a margin requirement for a market participant includes maintaining, by a processor associated with an exchange, an exchange account reflecting an exchange position resulting from a trade executed on the exchange for a product available via the exchange, the exchange account being maintained separately from a custodian bank account associated with a custodian bank, the custodian bank account reflecting a repo position resulting from a repo transaction facilitated by the custodian bank between the market participant and a counterparty to the repo transaction. The method further includes receiving data reflective of the repo position via a communication interface between the exchange account and the custodian bank account, and determining the margin requirement for the market participant based on the received data and the exchange position.