A long time ago I generated random Corn prices using +/- 1 penney incremental moves (just to keep it simple) from -10 cents to +10 cents as these were the limit moves corn could take. I was amazed at the results. When I ploted these out on a chart it looked just like the real corn charts.
I concluded comodities prices were randomly generated which indeed they must be. Still my charts had all the same patterns. And did it matter if they were random or not. Perhaps I was dealing with a natural effect.