(4)Where an institution's own credit standing drives the rates set by market indices which are also used as a reference for the remuneration of Additional Tier 1 and Tier 2 instruments of that institution, prudential concerns arise, relating to the correlation between the distributions on the instrument and the credit standing of the institution. The number and the diversity of institutions in the panel should be high enough to adequately reflect the activities in the related market. Therefore, if an institution issues an Additional Tier 1 or Tier 2 instrument with a floating rate or a fixed rate that will revert to a floating rate, the rate that it pays on that instrument should not increase when the institution's credit standing declines. Therefore, where the rate is linked to an index, the index should be sufficiently ‘broad’ to ensure that the institution's credit standing is not a main factor influencing the rates set by that index. The distinction should be made between correlation due to the entire sector suffering stress and affecting the benchmark rate, and correlation due to one institution's credit standing affecting the benchmark rate.