We measure the repo funding extended by money market funds and securities lenders to the shadow banking system, including quantities, haircuts, and repo rates by type of underlying collateral. Repo played only a small role in funding private sector assets prior to the crisis. The subsequent contraction in repo is relatively insignificant compared with the contraction in asset-backed commercial paper. Haircuts in our data rise less than in the interdealer repo market. While relatively small in aggregate, the contraction in repo with private-sector collateral particularly affected key dealer banks and led them to resort to the Fed’s emergency lending programs.