January Indicator of Future Stock Performance

As goes January, so goes the year. This particular phenomenon is what is referred to as the “January Barometer.” The following chart, which is from “Chart of the Day.com,” presents the average performance of the S&P 500 one, three, six, and 11 months following a January gain (blue bars) and following a January loss (gray bars). The chart illustrates that the S&P 500 has performed much better (on average) during the months following a January gain. In fact, 11 months following a January gain; the S&P 500 was up 89% of the time. For January 2007, the S&P 500 was up 1.4%.

The "January Indicator" has an impressive record. Does the indicator imply that since the market was up in January that eleven months from now the S&P 500 will rise over 12%? Evaluate the aforementioned question. In your evaluation, what type of information would you want to know?