The same system that the previous posts applied to the S&P 500 Index can be applied to other indexes, equities, or commodities. Below is a chart of Light Sweet Crude. The opening range is marked by the red circle and shows the highest high of the first three days (100.05) and the lowest low of the first three days (97.25). Subtracting this lowest low from the highest high gives us an opening range of 2.80. This value is then added to the top of the range in multiples to give us price extension levels once prices break above the opening range. The same value is subtracted from the low of the range in multiples to give us extensions levels once prices break below the opening range.
Light Sweet Crude (Click to enlarge)