COMEX was the commodity exchange at the center of the 1980 Silver Thursday market crash.
Silver Thursday occurred on March 27, 1980, when the price of silver plunged after regulators and lenders challenged the Hunt brothers’ attempt to accumulate a dominant position in silver. The brothers had used borrowed money and futures contracts, making their holdings vulnerable to a relatively small price decline.
COMEX, then the major U.S. marketplace for silver futures, changed its trading rules to restrict new speculative buying. Margin demands increased, and the Hunts could not meet all of their obligations when prices fell. The resulting financial stress threatened broader market disruption and required emergency credit arrangements.
Silver Thursday differs from an ordinary stock-market crash because the central asset was a precious metal and the venue was a futures exchange. The event is remembered as a warning about leverage, concentration, and the risks of trying to control a commodity market.