S&P 500 futures rallied to start the week, climbing back to 6,700 and gaining about 1.5% after bottoming on Friday. Volatility, which had spiked on Friday, moved significantly lower as the rally continued. Looking ahead, the economic calendar is light, but traders will be paying attention to the release of the NFIB Small Business Optimism Index and the start of bank earnings, which could set the tone for the quarter. The highlight of the day will be commentary from the Fed Chair, who is set to speak on the economy and policy.