I know there is an FX forum but I thought I'd ask here because a lot of you are math and statistic guys, which I ain't. Does it make sense to create a custom index in my charting program (Sierra Chart) of, for instance, the AUD, using the pairs I trade - AUDCAD, AUDCHF, AUDJPY, AUDNZD, AUDUSD, EURAUD (inverted for the index, of course), GBPAUD (inverted). I could then measure the performances of the pairs against the index via relative strength. Is this a dumb idea? Thankye!