As of Aug. 21, the conglomerate owned more than 605 million shares in a leading bank, a holding valued at $29 billion, making it Berkshire's third largest position. While this financial stock has produced a total return of more than 118% in the past five years, Berkshire has been a notable seller in the past year or so.

Investors have sharply different responses to UnitedHealth Group’s ongoing legal, regulatory and financial turmoil.

Berkshire Hathaway's $1 billion homebuilding investment indicates Warren Buffett's confidence in a future U.S. housing market rebound.