Warren Buffett and his team have built up an equity portfolio worth nearly $295 billion at today's prices. It's chock-full of value stocks, but Buffett's focus when buying stocks is investing in great companies. In other words, it's only a real value if the stock is underpinned by a top industry player.

This investment signifies Buffett's re-entry into UNH after liquidating his entire position back in 2010, indicating that he perceives significant value at