List any weekday patterns that you know of. I did some study on past daily data of the Dow Jones, and I think we could say that there's been a strong (and constant) tendency in the past 20 years, to go up in the first three days of the week (especially on mondays), and go down, or nowhere on average on the last two days. In other words, if you sum up all gains and losses of the past 20 years, and divide them by week day, you get this: Monday 105% Tuesday 58% Wednesday 39% Thursday -14% Friday 7% In the past 20 years the Dow Jones daily monday to wednesday gains add up to 200%, which is not just 200% because they are "compounded" daily (it goes from 2000 to 11000). Yet on thursday and friday, they add up to -7%. I think it is a pattern. Any comments? You know of any others?