President Donald Trump sought a billionaire investor's advice twice on whether he considered Amazon a monopoly during a dinner this summer, weeks before federal regulators signed off on the e-commerce giant's acquisition of Whole Foods Market. Leon Cooperman, a former partner at Goldman Sachs who runs the hedge fund Omega Advisors, said Thursday he attended a dinner with 10 people in July during which President Trump twice asked him the monopoly question. Cooperman, whose fund owned about $10.3 million of Amazon stock at the end of the third quarter, said on CNBC Thursday his answer to the president was no.