This paper studies the question of the economic scale of financial institutions. We show that banks actively smooth book equity by adjusting payouts to achieve a desired trajectory of book equity. The countercyclical nature of net payouts of financial institutions leads to procyclical book leverage, while market leverage is nearly entirely reflective of movements in book-to-market ratios. There is an apparent structural break after the 2008 crisis, indicated by the banking sector's subdued growth rate relative to pre-crisis levels. Market volatility dampens the intermediary leverage cycle. We draw conclusions for theories of financial intermediation and for capital regulation.