Buffett watchers cheer Berkshire's Apple and UnitedHealth bets — but wonder why he's sitting on so much cash

Warren Buffett's last trades as Berkshire Hathaway CEO are capturing particular attention ahead of his retirement at the end of this year. Business Insider asked three longtime followers of the legendary investor what they thought of them.'The perfect Buffett play'Berkshire built a $1.6 billion stake in embattled insurer UnitedHealth, its latest portfolio update showed. The stock has nearly halved over the past 12 months to trade at five-year lows as investors fret over earnings, federal investigations, p ...