mw (1)Printed your instructions. (2)you wrote: ". Do a linear regression of price of QQQs against time in days since the closing high on July 5th." Question? (1)Does that LG have a number of days in it calculation? (2)If so, what are the days. (3)If not, How do I back test? edit: (4)Need more info on RL? (a)Did you do LD on semiLog or regular time scale. (b)Chart would help.