http://en.wikipedia.org/wiki/Foreign_Agricultural_Service "In 1972 a short grain crop in the U.S.S.R. resulted in the Soviet Union quietly concluding grain purchasing contracts from a relatively small number of the secretive private multinational grain traders who dominated world trade in cereals. Because crop surveys in mid-spring had given the impression of a normal crop, FAS's agricultural attaché in Moscow chose not to follow up with additional crop observation travel, and thus missed a severe drought that set in after the last trip. As a result of this lapse, international grain traders and exporting nations were unaware of the Soviets' dire need for massive grain imports. By the time the scope of Soviet purchases became known, the U.S.S.R. had locked in supplies at low, subsidized prices, leaving other importers and consumers scrambling for what was left at significantly higher prices." I remember reading somewhere (but I don't remember where) that about 25 % of the Soviet population could have died of starvation because of that famine. http://en.wikipedia.org/wiki/Richard_Dennis "the 1970s, an era of repeated crop failures and the "Great Russian Grain Robbery" of 1972, when agents of the Soviet Union secretly purchased 30% of the U.S. wheat crop in the space of a few weeks." --- We may be witnessing a similar event now. We could experience 20 limit up days in a row, or 30 days, or more. Real panic could set in. Central bankers can not produce grain. Nobody knows for certain what will happen.
I remember reading in a book (I believe on options) that even in a lock limit market you can basically exit (fully hedge) your position with a synthetic long/short in the options market. Obviously this is not something you want to have to deal with but it can be a way to limit your losses (or lock in gains if you're positioned the right way). I also believe I read that some exchanges will mark your positions to market using the implied price from synthetic long/short option positions.
I have, probably, one of the most amazing futures stories that happened to me in the early 80's that I'll relate this afternoon when I have the time. Check back later.
Duke & Duke?? It happened during the time the Hunt brothers tried to corner the silver maket. Of course, no one knew what was going on at the time.