Warren Buffett has long complained that Berkshire Hathaway has become so huge that it’s difficult to find acquisitions that are both undervalued and large enough to make a material difference to the company’s bottom line.

Berkshire Hathaway fell 2.8% in premarket trading on Monday after revered investor Warren Buffett said he would be stepping down as chief executive of the conglomerate after 60 years at the helm.