As January goes, so goes the year

That’s an old, old Wall Street adage. So old, in fact, that I couldn’t even track down its origins. What the maxim means is that the direction of January foretells the stock market’s direction for the rest of the year (February through December) that is. Financial journalists love to pull this one out every year, particularly since a little quick math is impressive. In the 82 full years since and including 1926, this metric has worked 70% of the time. Considering markets are either up or down, 70% is much better than the coin flip odds would suggest. Or is it?