Summer may be the perfect time for the average investor to "sell in May and go away," but professional traders could miss out on some big gains by hitting the beach.
In a Wednesday note, Raymond James analyst Andrew Adams noted out the S&P 500's average price return between May 1 and Sept. 30 between 1990 and 2016 is just 0.01 percent.
So generally the 'Sell in May' strategy has worked.
But, trading in the summer months could still be profitable for nimble traders if they hang around because the market tends to have big swings. In his Wednesday note, Adams points out that the market has posted big gains during some summer months, only to fall back to earth before October.