NEW YORK (TheStreet) — The charts below offers some pretty compelling evidence that the old Wall Street chestnut “Sell in May and walk away” has some currency.

Nonetheless, I think another Wall Street mantra trumps the “sell in May” theory this time. Specifically: “Past performance does not guarantee future results.” Here’s why this summer could be different (notice I did not say, “is different,” perhaps the ultimate statement of hubris. If you are in your 20s, ask your parents about the first Internet bubble.)

Here’s my reasoning.

First, this is now the 13th straight quarter of better-than-expected corporate earnings. Eighty percent of S&P 500 companies have reported above analyst estimates, and earnings have been up 11.4% year over year.

Second, this is an election year. During elections years politicians give or engineer goodies for voters: lower unemployment, lower gas prices and more funding for education. Apparently, the strategy works. Since 1932, the median gains during election years has been as follows: May: 1.09%; June: 1.88%; July: -0.67%; August: 0.87%.

If you are a trader or speculator, I’d recommend spending some time trolling for opportunities among either very strong or very oversold consumer staples stocks. The S&P Consumer Staples sector has averaged 4.7% from May to October, while the S&P 500 as a whole has averaged just 0.9%. As always, though, take every financial mantra with a little grain of salt.