Elliott Investment Management's managing partner Jesse Cohn said on Wednesday he believes e-commerce platform Etsy will generate "significant, multi-year upside." Elliott, one of the world's most prominent investors, has a 13% economic stake in Etsy, including both common shares and swaps, a person familiar with the matter told Reuters in February. At the Sohn Conference in New York on Wednesday, Cohn said Elliott's stake was over 10%.