You're probably familiar with the old adage "Sell in May and Go Away," but TheStreet's Stephen Guilfoyle says it's just a "silly idea." He points out that it is called the "Halloween Indicator in reverse," because folks like to get into stocks for the winter and get out of them for the spring and summer.

Guilfoyle looks back 89 years to when the Dow was reconstructed in 1928. In that time, May has been positive 50 times, negative 30 times -- and the average return is 0.0%.

Watch more of TheStreet's Trading Strategies: Sell in May and Go Away