There's an old stock market adage to the tune of "Sell in May and go away." There's a bit of truth to this, since returns are lower on average for the period of May through October, versus November through April.
But some experts think this year might not hew to tradition. The S&P 500 is flattish year-to-date after a wild ride higher at the beginning of the year, with a lot of volatility in between. After some down days in April, some pundits are seeing an upside correction coming in May.
While the S&P 500's total return in the May-through-October period has averaged just 1.2 percent in the past 20 years, it has nevertheless finished higher 70 percent of the time. During the November-to-April period, by contrast, the S&P was up 85 percent of the time, averaging a 6.2 percent total return.