Professor Ronald J. Colombo joined several other securities law professors in signing an amicus brief in the Supreme Court case Morrison v National Australia Bank Ltd (filed Feb 26, 2010).

Professor Colombo and the amici argue that the jurisdictional reach of the primary antifraud provision of the 1934 Securities Exchange Act (Section 10(b)) does not extend to persons who purchase or sell securities outside the United States. The amici argue that both original intent and policy reasons support this more narrow reading of Section 10's jurisdictional scope.