According to online reports, Buffett said at the Berkshire Hathaway shareholders 'meeting that so far this year, we have not made any stock repurchase, and our company's repurchase mechanism will be relatively conservative. Companies that buy back their own shares will incur high taxes,"which does make the buyback slightly less attractive," Buffett said, adding that if companies believe their shares are almost certainly undervalued, they will buy back shares.