Quote from bone:
Atticus, in the past 14 months I have worked with one HF and another large Chicago private equity firm who spread baskets of stocks against notionals every second of the trading day in an omnibus account for ridiculous size. Whether you do 507 shares of SPY or 1 ES contract, the primary concern is slippage and the ability to move size.
Your size is immaterial to this discussion. Equal weight would result in a ~17:1 ratio in XLE to ES (not beta weighted). Price, not notional, otherwise you end up with a 98% XLE weighting in this case. Your chart of 851 XLE to ES is just a silly mistake. Admit you f*cked up and let's move on... and don't show that chart to your HF heavies.