Warren Buffett's message to investors and Berkshire Hathaway shareholders in his annual letter. Berkshire's growing cash position and what it might say about his view of the investing opportunities out there.

So it’s tougher to forecast economic and political trends, and to model investment and business risk based on those expectations, at a time that seems more of a major upheaval than a momentary shift.

Warren Buffett is a gifted teacher who explains complex topics in a digestible format. This year he touched on Berkshire Hathaway’s massive cash hoard, among other items.