What could drive the S&P 500 even higher?

As the S&P 500 continues to notch record highs, questions have arisen around concentration, sentiment, and valuations. So what's really driving US equities – and can the rally continue? John Flood, head of Americas Equities Sales Trading in Global Banking & Markets, discusses with Goldman Sachs Research’s Chris Hussey. Learn more about your ad choices. Visit megaphone.fm/adchoices