Buffett: The massive scale has become an obstacle to Berkshire's performance.

Jin10 News May 3, in discussing Berkshire’s holdings in Japan’s five major trading companies (Mitsui & Co., Mitsubishi Corporation, Sumitomo Corporation, Itochu Corporation, and Marubeni Corporation), Buffett turned to one of the biggest challenges facing his enterprise group: the scale issue. “It’s unfortunate that Berkshire has become so large,” Buffett said. “For Berkshire, size is the enemy of performance, and I don’t know of any good way to address this issue,” he added, “but it’s not an unsolvable problem.”