With regard to short selling, or more precisely, net short positions, two sets of measures have been taken: lowering of thresholds (a) and prohibitions (b). These measures are based on the provisions of Articles 20 and 28 of the Regulation of 14 March 2012 (Regulation (EU) No 236/2012 of the European Parliament and of the Council of 14 March 2012 on short selling and certain aspects of credit default swaps) which relate to the powers of intervention of national authorities (Article 20) and ESMA (Article 28) in the event of exceptional circumstances.