In the 2010 Greenwich Associates Global Custodian Prime Brokerage Study, institutional financial services consulting and research firm Greenwich Associates offered insight on the relationship between hedge funds and prime brokers, high water marks, counterparty risk concerns among hedge fund managers, hedge fund money raising, spreading of hedge fund cash and non-cash balances, use by hedge funds of leverage and separately managed accounts and hedge fund manager staffing.  The insights in the study were based on interviews with over 1,800 hedge fund managers across North America, Europe and Asia-Pacific.  This article summarizes the key findings of the study.