Found this in an article, lets see how well history repeats. Santa Claus Rally: 40% of the Dowâs Yearly Gain in a 17-Day Stretch posted on: December 05, 2007 A few weeks ago, I ran the numbers of how well the stock market does for each day of the year. I looked at all of the Dow closings going back to the beginning of the index in 1896. The best time of the year is a 17-day stretch from December 21 to January 7. Over the last 111 years, the Dow has gained an average of 3.39% during that 17-day period. To put that in some perspective, the Dowâs annual gain is 8.32%. This means that more than 40% of the Dowâs yearly gain has come during this brief stretch which is less than 1/20 of the entire year.