On the Mechanical Investing Forum, Fool.com, today, KBGlenn said: "Can't remember where I read it but some guy actually tried to quantify how much investors lose to simple human error in executing what they are doing. It was pretty high, something like around ~3-5% per year difference. That's a chunk of change if you add it up over time. Somewhere I'm sure my face is on the poster for this type of error."

Mine too.

Dave