Recent content by sfreewell

I've always used log change in creating a covariance matrix. Under what circumstance(s) would you use price rather than price change? Also, would you use ewma in calculating correlation as well?

GAT I'm waiting on delivery of your book and downloaded your spreadsheet on ewma calculation of standard deviation. In the mean time i was wondering if you use the dollar change or percent change when calculating vol. Also, when the forecasted vol for today do you calculate the ewma for the...