Have you looked at the 43-week SMA of individual screens? Seems this would be an interesting backtest.Yeah, I have. And it gets *really* complicated. Like...how do you compute the SMA of a portfolio that doesn't hold any stocks? I guess you could set up a paper portfolio and use paper trades in it -- but I could it quite likely for you to abandon the effort real quick.And all-in-all it doesn't really matter. The truth is that when the broad market is diving over a cliff, the best place to be is in cash, until the dust settles.a website that can do SMA of a portfolio of stocks, rather than just the indices or a single stock.For any serious work, you really need to do it yourself. I use Excel for all this kind of work.