We analyze securities trading by banks and the associated spillovers to the supply of credit.Empirical analysis has been elusive due to the lack of securities register for banks. We use a unique, proprietary dataset that has the investments of banks at the security level for 2005-2012 in...

We show that banks' risk exposure in one asset category affects how they report regulatory risk weights for another asset category. Specifically, banks report lower credit risk weights for their loan portfolio when they face higher risk exposure in their trading book. This relationship is...