On Tuesday, energy traders sent gasoline futures to their largest single-day drop in months as they unwound long positions ahead of the Department of Energy's weekly Petroleum Status Report.

June gasoline futures tumbled 9.5 cents on Tuesday, or slightly less than 4 percent, to finish the day at $2.31 per gallon. Traders were expecting a third consecutive week of inventory builds in gasoline and may have been nervous that the weekly report would show an even higher than expected increase in inventories.

The actual report showed an inventory build of 1.5 million barrels, not considerably more than expected, but also showed a marked increase in refinery capacity utilization.

While the inventory number was seemingly neutral for gasoline futures prices, the uptick in capacity utilization could prove to be bearish in coming weeks and could result in faster gasoline inventory builds if these utilization levels can be maintained or further improved.

However, the U.S. is fast approaching its summer driving season and gasoline inventories are far below the average for this time of year. It may be very difficult, if not impossible, for inventories to recover to normal levels until after the summer.

If this is the case, and consumers to not curb their demand for gasoline this summer, it could support gasoline prices for months to come.

CORN: Corn futures fell Tuesday after Department of Agriculture released its weekly Crop Progress and Condition report Monday.

The report showed that for the first time this season, corn plantings are ahead of last year's progress as well as the average progress for this time of year. Corn plantings were reported at 92 percent complete, versus last year's mark of 91 percent and the 10-year average of 87 percent.

Coupled with this reading on planting progress, the Department of Agriculture also reported on the average corn crop conditions for the first time this year. That report showed that the condition for the corn crop was at its highest level since 1994, a year that produced then-record yields.

According to Department of Agriculture's report, 78 percent of the U.S. corn crop was rated either good or excellent, ratings which indicate average to above-average yields at harvest. This compares to last year's reading of 66 percent and the 10-year average of 65 percent.

Both the planting progress and condition rating pressured corn prices on Tuesday as July corn futures closed down 11.5 cents, or slightly more than 3 percent. However, only two-thirds of the U.S. corn crop has emerged, so these numbers may be subject to wide revisions in coming weeks as more corn emerges in the northern U.S.

COPPER: A confluence of actions pushed copper prices down by almost 3 percent on Tuesday. A strengthening dollar, weakness in energy futures before the Department of Energy's weekly energy report and slipping bulk shipping rates all gave copper traders an excuse to sell on Tuesday.

Copper prices have rallied recently on the back of strong Chinese imports. This import demand has also pushed shipping rates to record levels.

However, in the past week, shipping rates fell each trading day, an indication that import demand may be weakening in China. Though China imported a record amount of copper in the first quarter of the year, some traders have started to believe that this may have been the bulk of China's import demand for the year, rather than an indication of strong import demand for the entire year.

If this turns out to be the case and China's copper demand slows, it could pressure prices lower in coming weeks.

Walt Breitinger is vice president of commodities at A.G. Edwards and Sons. He can be reached at (219) 738-6460.