We study the effects of mark-to-market accounting (MTM) for banks following the originate-to-distribute lending model. Banks have expertise in originating loans but it is costly for them to retain the loans on their books. We study how the accounting measurement of the retained loans affects the banks' origination and retention decisions.We show that, relative to historic cost accounting (HC), MTM has three consequences.First, it improves the accuracy of loan valuation ex post. Second, it forces banks to retain more risk exposure on their own books. Finally, it can reduce ex-ante origination efforts and lower the average quality of loans in the economy. To the extent that lower loan quality and banks' excessive risk exposure are two important ingredients for the recent financial crisis, we identify one mechanism through which MTM could contribute to financial crises.