Abstract: This report is the first in a series of reports by the Program on International Financial Systems on enhancing the market structure for trading U.S. Treasuries (“cash Treasuries”) and for repurchase agreements of U.S. Treasuries (“Treasury repos”). In this report, we assess whether policymakers should mandate central clearing in both markets. In future reports we will consider whether policymakers should require the public disclosure of transaction-level data and evaluate design considerations for the standing Treasury repo facility.