This is an adjusted chart to display price from the actual roll using volume for the roll...so when the volume of the nearby contract exceeds the front month contract the chart is rolled so that the front month is always the highest volume...I went back and adjusted it to the beginning of the year, the rest before that is rolled at 12 before contract end...which is pretty close. The move from the July to Sept corn contract resulted in a jump of that Sept contract moving to the Dec contract because of the volume.
If your trying a long here you would protect with a close below 520.50... The safe and sane way would be to wait for a close above 595...but what fun would that be?
Sp!ke