I have recently read an interesting article on so-called 1-5 trades on futuresmag.com (http://www.futuresmag.com/2011/07/01/using-spxoex-options-spreads-to-take-a-directional?t=options) The article discusses two spreads on two indices that are traded against each other. The trader simply buys a bull call spread on the SP500 and sells a bull call spread on the SP100. The idea is that the trader speculates on the spread between the SP500 and the SP100. More precisely, the spread is SP500-2xSP100. Does anyone have experience with this kind of trades? How do you construct a pnl graph for this kind of trades? Is the PnL graph three-dimensional, where the price of the SP500 is plotted on one axis and the price of the SP100 is plotted on the other axis? The trade is also taught by Randomwalktrading.com (I have no affiliations with this company). Has anyone taken their course or purchased their books? Many thanks in advance!