One of the benefits of attending the Berkshire Hathaway (NYSE:BRK-B) shareholders' meeting is learning from the great value investors and Buffettologists who also make the yearly trek to Omaha. In this multipart series, Fool analyst Rex Moore speaks with Lawrence Cunningham, author of The Essays of Warren Buffett: Lessons for Corporate America. The book offers a unique approach by arranging all of Buffett's shareholder letters thematically, rather than chronologically.

Today, Professor Cunningham explains how Berkshire's enormous cash position led to purchases of regulated companies with a built-in moat.