Stone Lion Capital Partners, L.P. (Stone Lion) (plaintiff) and Lion Capital LP (Lion Capital) (defendant) were investment management companies. Lion Capital owned registered trademarks for “LION CAPITAL” and “LION” in connection with “capital investment consultation.” Stone Lion filed an intent-to-use application for “STONE LION CAPITAL” in connection with “investment advisory services.” Lion Capital opposed the application on the ground that the mark was likely to cause confusion with Lion Capital’s marks. Both parties stated that their clientele was sophisticated. The Trademark Trial and Appeal Board rejected Stone Lion’s application. Stone Lion filed suit appealing the ruling. Stone Lion argued that the scope of its investment services was not as broad the board found, and that the board erred by considering the perception of unsophisticated clientele.