Another anomaly that can be investigated empirically, even if it is not justified by any logical reason, is the January barometer effects. Some research argues, regarding S&P 500, that a positive January is usually associated to a positive year, instead a negative January is a predictor of a negative year.
In their paper “Seasonal patterns and calendar anomalies in the commodity market for natural resources”, T.Levy and J.Yagil wrote:
“According to Cooper et al. (2006), the other January effect, sometimes known as the “January barometer,” is related to the documented observation that stock market performance in January predicts market returns over the following 11 months. This effect predicts that if the January returns are positive, the returns for the next 11 months will be positive as well, but if January concludes with negative returns, the returns in the following 11 months will be negative as well.
For commodities, the returns for the 11 months following a positive January tend to be positive, but they are statistically insignificant. In addition, the returns for the 11 months following a negative January also are no different from zero. The only significant result is the relatively high number of positive January months for silver (20 vs. only 12 negative Januarys), platinum (23 vs. 9) and palladium (25 positive Januarys vs. only 7 negative Januarys).”