Stocks may be flirting with record highs, but don't get too comfortable, one strategist warns. 'We have to be on edge about a correction,' said Jeff Tomasulo, CEO & head portfolio manager at Vespula Capital. 'I am very cautious right now. Since 2009, we are up tremendously and when you have a move that we've had from the bottom, you have to be cautious.' The S&P 500 is up 211% since its March 2009 low. 'In certain sectors, we're overvalued and other sectors we're at fair value,' he added. 'We're looking at the positions we have in certain sectors like technology and biotech and we're cutting that back and taking our profits.'