The Oracle of Omaha recently lost a big takeover battle. : Topline: Billionaire investor Warren Buffett’s latest dealmaking efforts suggest that the stock market is overvalued (as noted in this CNBC analysis), as the Oracle of Omaha recently lost to a private equity firm in his latest takeover bid—despite having a record $128 billion in cash on the sidelines, which he is finding increasingly difficult to spend on acquisitions. Big numbers: Berkshire Hathaway shares are lagging the broader S&P 500 index by more than 15% this year.