Warren Buffett, the Oracle of Omaha, is the master of the sly stock grab, quietly amassing stakes in undervalued companies while the market naps. His recent moves, like boosting Berkshire Hathaway Inc's BRK BRK holdings in Occidental Petroleum Corp OXY and VeriSign Inc VRSN, prove he's still got a nose for hidden gems. Let's peek into Buffett's covert playbook and see if these picks are diamonds in the rough or just shiny distractions. Track BRK-A stock performance here. The Art Of Stealth Investing Buffett ...