[Alfredo]

The purple line indicates the level of "open interest", which is a technical term used to indicate the number of futures contracts existing during the subject time period (here, each chart bar represents one week's price range). The vertical red lines are a measure of volume of contracts traded during each week. Interpreting these things as they apply to price action is a pretty esoteric study, but fortunately not at all relevant to the chart at hand for our purposes.

The "fudge factor" is a pretty important component in the equation the government uses to calculate statistics, especially inflation numbers. Don't know why they bother - no one is fooled an more.

If you're going to produce ethanol - the value of which is a whole separate debate - sugar is a far more efficient source material than corn. Now let's see - how large is the sugar industry lobby and how large is the corn industry lobby in the U.S.? Political considerations, anyone?