Liz Ann Sonders, Sr. Vice President & Chief Investment Strategist at Charles Schwab, says on a 50-day average basis, the spread between the S&P's breadth relative to the Nasdaq's has never been wider than now. She says we are in lofty valuation territory. She says rising interest rates aren't in and of themselves a risk to the overall equity market, but they do put downward pressure on pockets of excess valuation. She discusses market P/E ratios.