Most Active Month

While cogitating the behaviour of investors (see Halloween and Investor-think) I notice that October is often (usually?) the most active month: More shares trade in October than in any other. Here are the DOW stocks (over the last 10 years) (summing the monthly volumes). Click on the picture for an enlargement. P.S. The 10th month is October. Now why is that? Does everybuddy dump their stocks, concerned that October is the month that's had all them crashes? But September is (usually) the worstest month: Click! If'n I can't figure the thought processes that influence my wife's buy-sell decisions,** how will I ever figure out how investors think, eh? **You'd think I could figure that out ... we'll soon be celebrating our 50th wedding anniversary!