Once upon a time, if you had a good idea you might write a book about it. But then everyone figured out books were bullshit. If your idea is so good, how come you aren’t rich? So now when people have good ideas, they start hedge funds.
Weekdays in August are a good time to own stocks. The end of October isn't bad either. Christmas can be fine for equities as well.
What these dates have in common is that they are times when Congress isn't in session. Back in 1991, a Wall Streeter named Eric Singer noticed that equities that year tended to do better when lawmakers weren't in Washington. He published an op-ed in Barron's proposing that the correlation was no coincidence.
Later, he looked at a wider timeframe and went around the squash courts of New York telling people he might write a book about his thesis. Now Singer is going one step further. He has created a hedge fund, Singer Congressional Fund. Its goals include making money from the Congressional calendar.
Make Money When U.S. Congress Is Out of Session [Amity Shlaes]