The January Effect

The January effect proposes that stocks gain in the first five trading days of the year (correct 70% of the time). Average first week of January returns...

Dow: 0.8%
S&P 500: 0.8%
Nasdaq: 1.4%

The January Effect is not to be confused with The January Indicator or Barometer which proposes that as January goes, so goes the market (correct 90% of the time). Average month of January returns are...

Dow: 1.1%
S&P 500: 1.5%
Nasdaq: 3.5%

Compiled from over 100 years of data for the Dow, 75 years for the S&P 500, and 35 years worth of data for the Nasdaq.

Unrelated but interesting: The Dow has had positive returns 17 of 25 presidential election years. I'll have more about the Holiday Rally that wasn't later.