1. Member States shall ensure that competent authorities, in line with the methodology for calculation determined by ESMA, establish and apply position limits on the size of a net position which a person can hold at all times in commodity derivatives traded on trading venues and economically equivalent OTC contracts. The limits shall be set on the basis of all positions held by a person and those held on its behalf at an aggregate group level in order to:
(a) prevent market abuse;
(b) support orderly pricing and settlement conditions, including preventing market distorting positions, and ensuring, in particular, convergence between prices of derivatives in the delivery month and spot prices for the underlying commodity, without prejudice to price discovery on the market for the underlying commodity.