It's been referred to as the last bastion of unfettered, pure capitalism.  The Chicago Mercantile Exchange has hosted the "open-outcry" pits since 1848, but the computer revolution is finally ending the practice, and pit trading will cease in most markets at the close of business today.

Reuters:

A few dozen Chicago traders will don their multicolored jackets to trade soybean and forex futures the old-fashioned way one last time on Monday, marking the end of 167 years of open-outry trading in the city where it was born.

Barring a last-minute delay by U.S. regulators, CME Group Inc will end most of its open-outcry futures operations in Chicago and New York after the closing bell on Monday, concluding a tradition that once epitomized global financial markets but succumbed to the efficiency and speed of machines.

The din of raucous shouting and frenzied hand gestures at the cavernous Chicago Mercantile Exchange floor has faded over the years, and now makes up only 1 percent of total volume. The exchange's more active options pits will remain open for now, although they too are losing ground to electronic dealing.

CME is moving ahead with the plan despite resistance from a small group of floor brokers and traders in Chicago, who have argued the closures would hurt end-users in the Treasury and Eurodollar markets. Last month, they asked the U.S. Commodity Futures Trading Commission (CFTC) to open a 90-day review of the plan.

The CFTC has until close of business on Monday to make a decision about whether to delay the closures.

As the birthplace of futures trading, and with strong ties to the traditions that surround it, the CME held off the shift to an all-digital platform longer than most other exchanges.

In 2012, CME rival IntercontinentalExchange Inc silenced 142 years of open-outcry trading in New York when it closed the trading rings for sugar, cocoa and other soft commodities. They were the last of ICE's markets to go all electronic.

More than a decade earlier, the London International Financial Futures Exchange became the first major futures house to abandon open outcry when it switched abruptly to all-electronic trading.

Last Thursday, traders remaining on the CME's grain and financial floors in Chicago gathered for a group picture in the soybean futures pit. They shared memories of their experiences in the 167-year-old grain pits with each other and on Twitter.

One of the more popular tourist attractions in Chicago used to be the CME, where the frenzy of trading became an entertainment itself.  The jumping, shouting, gesturing traders would do anything to get the attention of the pit men.  Seconds lost could mean millions of dollars.  It was easily the most stressful job in America to be a trader in the CME pits.

It's still stressful, but with the advent of electronic trading, there is little need for the pits.  Trades can be made in a blink of an eye, making the human connection obsolete. 

There is actually a game based on open outcry trading.  "Pit" is a wild card game where players try to "corner" the market on a commodity like wheat, corn, rye, or barley.  The commodities used in the game may have changed over the years, but the fun hasn't. 

So the trading pits of the CME will join other American traditions, treasured but gone.  There's a lot to be said for efficiency, but it's sad to lose such an ancient tradition.