Corn futures rallied sharply this summer as one of the worst draughts in the last 100 years hit the Midwest.

With most of the nation’s corn crop grown in the region, speculators were quick to add bullish positions. Large speculators built the biggest net long position in corn contracts since last September.

Commercial hedgers built the biggest short position since June 2011.

With the large speculators buying so heavily, the price jumped from a low of $551 in June to a high of $849 in August. That is a jump of 54 percent in approximately two months.

The problem is that with large speculators so bullish, there is little room to the upside and very few investors on the sideline that can extend the rally.

When there are no buyers, only sellers are left. And this is what concerns me about the price of corn.

With the price of corn hovering near its all-time high and such a one sided Commitment of Traders report, it seems the tides are about to shift.

If you don’t have a futures trading account, but still want to take advantage of a downturn in corn prices, there is an exchange-traded fund (ETF) for corn.

The Teucrium Corn (CORN) ETF tracks the movement of corn futures. You could sell the fund short or buy long-term puts on the fund. Should corn fall over the next few months, your bearish positions will gain in value.