Every Weekly Dow Close

I’m an incessant data fiend. If something has data, I’m all over it. Even as a kid, I could swallow baseball statistics whole. Batting averages, slugging averages, it didn’t matter. I have no idea why I do it. I just do.
I’m afraid I’m incurable. Any twelve-step program would backfire. I’d count the steps and find a moving average. I’m pathetic, I know.
Here’s an excel spreadsheet of the Dow’s closing value for every week. And by that, I mean week. Starting from when Mr. Dow began calculating it by hand. All 5,698 weeks from May 12, 1896 until today.
Some stats: The Dow’s average weekly gain is puny, just 0.13% (this doesn’t include dividends). That’s equal to a $76 stock rising 10 cents in a week.
The weekly standard deviation is 2.56%. So the market’s average weekly swing is nearly 20 times its average weekly change. So 95% of what happens each week is pure noise. It’s totally meaningless.
And that noise hangs around for a long time. Even after five years, the Dow’s average return is still equal to one standard deviation (for cool math types, 1.0013^260 is roughly 2.56*[260^0.5]).
Think about that. That means that there’s roughly a 1-in-6 chance that the Dow will be exactly where it half-a-decade from now. Five years, zippo capital gains.
The Dow is currently 2.8% higher than where it was five years ago today.
Let’s hope the next five years will be better.

Posted by on January 19th, 2006 at 11:03 pm


The information in this blog post represents my own opinions and does not contain a recommendation for any particular security or investment. I or my affiliates may hold positions or other interests in securities mentioned in the Blog, please see my Disclaimer page for my full disclaimer.