In the video below, Fool analyst Blake Bos takes a look at three of the world's biggest investing powerhouses and talks about what they're buying today. He discusses the sovereign wealth fund Qatar Holdings and its move to increase its stake in Tiffany's (NYSE:TIF) by $172 million, updates investors on the continuing soap opera battle over Herbalife (NYSE:HLF), and, of course, takes us through what Warren Buffett is buying at the moment.