44. The stock of HQLA should be well diversified within the asset classes themselves (except for sovereign debt of the bank’s home jurisdiction or from the jurisdiction in which the bank operates; central bank reserves; central bank debt securities; and cash). Although some asset classes are more likely to remain liquid irrespective of circumstances, ex-ante it is not possible to know with certainty which specific assets within each asset class might be subject to shocks ex-post. Banks should therefore have policies and limits in place in order to avoid concentration with respect to asset types, issue and issuer types, and currency (consistent with the distribution of net cash outflows by currency) within asset classes.