Nasdaq hits record; bank earnings validate Wall Street rally

An increase in Facebook pushed the Nasdaq to a record high on Friday and the S&P 500 also rose after major U.S. banks kicked off the fourth-quarter earnings season with strong results. Wall Street has surged since President-elect Donald Trump's unexpected election victory on optimism he will cut corporate taxes, spend on infrastructure and deregulate banks. With stocks trading at price-to-earnings valuations well above historical averages, many investors believe further gains will depend on