Jim pretty much hit it.
I grew-up on the farm, majored in Econ. and Business Administration. Now, I'm in my cube working for a bank typing this.
Anyhow,
The esaiest way to explain it, is, if your see metals, oil, stocks and grain all move in the same direction roughly the same amount percentage-wise in one day, its not that the values of these commodities are changing as much as it is the value of the money buying them is changing.
With things trading in global markets everybody's doing the math to convert to local currency. For example, The Japanese don't care how many dollars they pay for a bushel of soybeans for food, or for that matter a ton of copper to make electrical systems in cars. They want to know how many Yen it costs.
I think it was 2006 or 2007 when my dad told me of the first predictions of $6.00 corn. I said that's the dumbest thing I'd ever heard. How could anyone make money buying $6.00 corn? Ethanol wouldn't make sense. Hogs wouldn't make sense.
Come to find out, all it really takes is for the dollar to get cheaper. $80 Crude oil means $3.00 gas and then, all of the sudden, $6.00 corn isn't so out of line. Guy who made that prediction was smarter than me.
I know some older guys used to get into the habit of thinking about how many bushels of corn something cost instead of how many dollars. I like that strategy.
