Articles about the “commodities market” are a bit brain twisting if you’re not in that biz. For example:

When you buy or sell a financial commodity product by a future on the exchange like the London Metal Exchange, you just pay a fee, an initiation margin call, and then your broker buys on your behalf the full position. If the market moves against you, you pay a bit more margin, and if the market goes in your favor, you get a bit more money from your broker. As the market was starting to go up, the Big Shot position was underwater and the brokers were demanding more money from this position. When the whole market is caught in that situation, we get a short squeeze, which forces everyone who was betting on the downside to buy back their positions because they are facing billions of dollars of margin calls. It got to a point where the market went up 250 percent in about thirty-six hours, with margin calls in the billions. The exchange had no option but to shut down trading. This is a very unusual situation; it only happens once every few decades that a major commodity market has to shut down.

What if a similar situation were to happen in the oil, wheat, or gas market? What would be the consequences for the global economy? Are the commodity traders and the commodity exchanges “too big to fail”? Their failure will bring chaos to the global economy not through the credit channel but through the real economy, perhaps through shortages or crippling high prices.

Phenomenal World (which I never heard of, but this is a transcript of an interview with a Bloomberg reporter)

So this is how the first warnings of a serious global food crisis could come out. So watch the digital equivalent of the business pages.