From last week,
Use 424.00 as the swing point to start the week.
Above it, once it can clear the 432.50 major Gann square, look for the next one at 456.00. With a trade up to , or above the 432.50 major Gann square and closing below it, should send this market back one major Gann square at 408.00.
As you can see on the chart, Monday's low was 423.00 and it never closed below the 424.00 swing point for the week.