Should investors 'sell in May' this year?

The old adage of "sell in May and go away" pops up on Wall Street every year. According to LPL Financial, the S&P 500 returns 1.7% on average between May and October. It returns 6.8% on average from November to April and over the past six months, the index is up close to 30%. Ryan Detrick, LPL Research chief market strategist, and Stephanie Link, chief investment strategist and portfolio manager at Hightower, joined "Squawk Box" on Monday to discuss.