September appears to be the worst month for Seasonal Affective Disorder, which may be the missing link for why the month is so bad for the stock market.
The monthly composite data are plotted in the chart above. Notice that the highest reading is in September. I suspect you already know intuitively that the picture this chart is painting could be accurate, since many of us begin to experience the depressive effects of SAD around Labor Day — when summer comes to an end, the days shorten and children return to school.
That’s strong circumstantial evidence. Even more compelling is what emerged when the researchers studied the correlation between SAD and mutual fund flows in Australia. Since that country is in the southern hemisphere, the incidence of SAD should be the mirror opposite of the U.S. pattern. Sure enough, mutual fund flows in Australia follow the same pattern as in the U.S., shifted six months forward.
I do expect new 52 week lows before mid October