Berkshire Hathaway Inc. (NYSE:BRK) (NYSE:BRK) executives have recently made significant sales of the company’s stock, raising questions about the market’s valuation. The sales, which come amid a historic market cap milestone, could indicate a shift in the company’s outlook. What Happened: On Monday, it was revealed that Ajit Jain, the insurance chief at Berkshire Hathaway for nearly four decades, sold over half of his Berkshire stake, amounting to $139 million. This marked Jain’s largest stock sale since joining the company in 1986. These sales, which occurred as Berkshire’s Class A stock clos…