Certainly, the risk of a procyclical effect of the activation of the buffer has not materialized. Most German banks have sufficient levels of capital in excess of the regulatory minimum, implying that a CCyB of 0.25% is likely not binding. In addition, the one-year phase-in period gives banks sufficient time to comply with the buffer requirement.
The exact calibration of the buffer is certainly at the lower bound; other European countries have set higher buffer rates. The Bundesbank will continue monitoring the potential build-up of vulnerabilities, bring this analytical work into the Committee, and will publish its next Financial Stability Review in November 2019.