BofA's Savita Subramanian explains why she's neutral on the S&P 500

"I think the big risk to the S&P 500 is that it's done well in an environment of benign inflation," Savita Subramanian, head of U.S. equity and quantitative strategy at Bank of America Merrill Lynch, told CNBC's "Squawk Box" Tuesday. "We've been in a goldilocks environment and the risk to that thesis, I think, is elevated today, so that's another reason we're neutral and not bullish on the S&P 500. We could potentially see a move in inflation that is actually negative for risk assets."