Chairman of the Hellenic Capital Market Commission, former Member of the European Securities and Markets Authority (ESMA) Board of Supervisors, Member of the ESMA Management Board, Chairman of the ESMA Market Integrity Standing Committee, dealing with cooperation, exchange of information and market surveillance, Kostas has been responsible for the whole capital markets legislative package during the Greek Presidency of the European Union (first semester 2014), Chairman of the working group on the benchmark Regulation. One of the two European Regional Committee (ERC) representatives to the IOSCO Board.