Since 1950 there is has been a pattern, that gives you a preview of how the stock market may go for the next year. It is called the January Barometer.
Basic, you look the the S and P 500 (SPX), and see what it does in January. Both the first 5 days of trading and the whole month of trading. And see what that correlates too in the the past.
The first 5 days of trading, give you about an 85% correlation, and 90 percent plus for the month.
Therefore, if the SPX goes up in the first 5 days, 85 % chance that will be the direction for the year. If we watch the whole month and it goes sideways, then a 90 percent chance the market will go sideways for the year.
Pretty cool little tool.