Brokers, who were not lending their own money, pushed risk onto the lenders. Lenders, who sold mortgages soon after underwriting them, pushed risk onto investors. Investment banks bought mortgages and chopped up mortgage-backed securities into slices, some riskier than others. Investors bought securities and hedged against the risk of default and prepayment, pushing those risks further along. In a purely capitalist scenario, the last one holding the risk (like a game of musical chairs) is the one who faces the potential losses. In the sub-prime crisis, however, national credit authorities (the Federal Reserve in the US) assumed the ultimate risk on behalf of the citizenry at large.