Losses on Lehman Brothers paper led one prominent fund to "break the buck" – that is, to fail to maintain a net asset value of $ a share – which undermined investor confidence in such funds and triggered significant withdrawals from funds that typically invest in private-sector debt.
In response, the Treasury established an insurance program for money market mutual fund investors, and the Federal Reserve introduced new programs to provide liquidity to money market mutual funds. In addition, the Federal Reserve authorized the Commercial Paper Funding Facility to provide a liquidity backstop for U.S. issuers of commercial paper.