Price action of wheat seems to signal continous selling into upside spikes. the selling subsides as we get further below 500. The market 'trains' the participants to give them the impression its headed down. As more shorts are placed, then on a given day you will see rapid short covering rally.
Thats why the wheat market is dangerous. Ultimately it will head higher, but day to day action is down. But one session can wipe out the gain on the sell side progression. Looking what happened Friday. One day can wipe out couple weeks price action. And the novices, can be caught short as the market spikes up consecutive days.