It may be a bull market for some commodities, but the pork belly is in danger of going belly-up.

The iconic futures contract, a staple at CME Group 's Chicago Mercantile Exchange since 1961, has seen its volume drop in recent years, prompting calls for the exchange to shut down trading altogether. Now exchange officials and the pork industry are trying to figure out a way to save the contract from extinction.

The pork belly, a slab of frozen meat from which bacon is cut, was once among the CME's most-traded commodities, earning the exchange the nickname the "House that Bellies Built."

But just six contracts changed hands in the month of November—fewer than uranium or palm oil. The once-bustling pork-belly pit has been moved to a corner of the CME's floor, an appendage to the lean-hog-trading pit.

Pork bellies once were synonymous with agricultural futures in the popular imagination. Billy Ray Valentine, Eddie Murphy's character in the 1983 comedy "Trading Places," memorably explained the market's mechanics.