Berkshire Hathaway Inc.’s cash pile soared to $381.7 billion in the third quarter, a fresh record, and operating earnings surged 34$13.5 billion, as the firm’s insurance underwriting profit more than tripled in a period marked by unusually low disaster activity, according to filings published Saturday. Earlier this year, Buffett appeared to be back on the hunt for deals, with the acquisition of a $1.6 billion stake in UnitedHealth Gr ...