Billionaire activist investor Carl Icahn on Wednesday lambasted BlackRock Inc (BLK.N), the world’s largest asset manager, as an “extremely dangerous company” because of the prevalence of its exchange-traded fund products, which Icahn deems illiquid. “They sell liquidity,” Icahn said in reference to BlackRock’s ETF business. Icahn was speaking at the CNBC Institutional Investor Delivering Alpha Conference in New York, sharing the stage with Larry Fink, chief executive of BlackRock.