(67)Since market abuse can take place across borders and markets, in all but exceptional circumstances competent authorities should be required to cooperate and exchange information with other competent and regulatory authorities, and with ESMA, in particular in relation to investigation activities. Where a competent authority is convinced that market abuse is being, or has been, carried out in another Member State or affects financial instruments traded in another Member State, it should notify that fact to the competent authority and ESMA. In cases of market abuse with cross-border effects, ESMA should be able to coordinate the investigation if requested to do so by one of the competent authorities concerned.