All usda reports are important and if you want to make a living at trading grains you have to pay attention. As for this past week, the market was anticipating a bullish report for corn throughout the week as evidenced by a very significant tightening of the spreads. The z10/z11 traded from even money to a high of 58 over today. This is telling the market something very important. I had an excellent week trading corn flat price and spreads only because I was paying attention to the spreads. I have a trading floor background as a local and as any local will tell you, knowing what is happening to the spreads will reveal much about the flat price. Regards, local
IV may not tell you much - IV is a measurement of uncertainty... when the report is due, of course the uncertainty is high, hence the jump in IV... but the realized outcome can be random: prices going up or down...