This article makes several valid points about the nature of commodities investing and its inherent risks. I've worked in the field of finance for many years. Currently I work with a firm that provides working capital to small businesses across the US.

I agree that a macroeconomic view is especially important in this case. In addition to the ramifications of the slowdown in China's market, I think that an additional factor is even more important.

Continuing manipulation of the gold and silver market that is occurring as countries are striving to control their currencies value and manage their debt, is a major factor in Glencore's current condition. And that is always beyond an individual investors control and many times overlooked when assessing profit potential vs risk.