(4)The disclosure regime for financial instruments that have a similar economic effect to shares should be clear. Requirements to provide exhaustive details of the structure of corporate ownership should be proportionate to the need for adequate transparency in major holdings, the administrative burdens those requirements place on holders of voting rights and the flexibility in the composition of a basket of shares or an index. Therefore, financial instruments referenced to a basket of shares or an index should only be aggregated with other holdings in the same issuer where the holding of voting rights through such instruments is significant or the financial instrument is not being used primarily for investment diversification purposes.