Macroprudential policies have recently attracted considerable attention. They aim at both strengthening the resilience of the financial system to adverse aggregate shocks and at actively limiting the build-up of financial risks in the sense of “leaning against the financial cycle”. One reason for the appeal of such policies is that, by explicitly taking a system-wide perspective, they complement macroeconomic and prudential measures in seeking to address systemic risks arising from externalities (such as joint failures and procyclicality) that are not easily internalized by financial market participants themselves (see CGFS, 2010). Against this background, the new Basel III regulatory standards feature the Countercyclical Capital Buffer (CCB) as a dedicated macroprudential tool designed to protect the banking sector from the detrimental effects of the financial cycle (see BCBS, 2010a). We provide the first empirical analysis of the CCB based on data from Switzerland – which became the first country to activate such a buffer on February 13, 2013. To reinforce banks’ defenses against the build-up of systemic vulnerabilities, the activation of the CCB raised their regulatory capital requirements, thereby contributing to the sector’s overall resilience. However, little is known about the CCB’s contribution toward the second macroprudential objective: higher requirements might slow bank lending or alter the quality of loans during the boom and thereby enable policy-makers to “lean against the financial cycle”. Up to now, policy debates have focused mainly on the quantity of aggregate credit growth. We aim to shift the focus of the debate towards quality, namely the composition of lenders and how tighter capital requirements interact with borrower risk characteristics. Does the CCB have the potential to shift lending from less resilient to more resilient banks, and from riskier to less risky borrowers? Based on our findings, our analysis advances the understanding of some mortgages.