The competent authorities
may deem a pair of currencies to be closely correlated only if the likelihood of a loss — calculated on the basis of daily exchange‐rate data for the preceding three or five years — occurring on equal and opposite positions in such currencies over the following 10 working days, which is
4 % or less of the value of the matched position in question (valued in terms of the reporting currency) has a probability of at least 99 %, when an observation period of three years is used, or 95 %, when an observation perio
...[+++]d of five years is used.