(80)It is therefore appropriate to require credit institutions and relevant investment firms to hold, in addition to other own fund requirements, a capital conservation buffer and a countercyclical capital buffer to ensure that they accumulate, during periods of economic growth, a sufficient capital base to absorb losses in stressed periods. The countercyclical capital buffer should be built up when aggregate growth in credit and other asset classes with a significant impact on the risk profile of such credit institutions and investment firms are judged to be associated with a build-up of system-wide risk, and drawn down during stressed periods.