I am plotting my P&L for two months now and noticed that it always goes down on thursday. I dont daytrade. i hold overnight positions. Till last week i chose to believe that its a coincidence. But it happend again today. I can see two ths were ruined by london bombings. I am thinking about always buying low on ths/fri and sell on wed. But may be I am seeing to much into it and it really is a coincidence. Any suggestions or statistics to support or refute this?