Buffett, Berkshire's chief executive officer and chairman, his investing deputies have been on one of Berkshire's biggest buying sprees, with about $41 billion of net purchases during first quarter
In his annual letter to Berkshire shareholders, Buffett said buybacks make 'good sense' when alternatives such as buying whole companies or more stocks appear 'unattractive'
The new US tax law was a windfall for Berkshire. Analysts at Barclays Plc noted that the lower corporate rate probably added $37 billion in the fourth quarter to book value
