The bankruptcy of MF Global means big changes to the way people do business – especially in the futures market.

Over the weekend, Chief Executive Jon Corzine searched for a buyer for the firm to no avail. MF Global officially filed for Chapter 11 bankruptcy protection on Monday morning. The firm’s stock price had suffered over the previous week amid investor concerns over a recent quarterly loss and $6.3 billion of exposure to European sovereign debt.

Traders in Chicago at the Chicago Board of Trade and Mercantile Exchange were taken aback by the news. MF Global has a huge presence in the open outcry pits of the exchanges. CME Group, along with InterContinental Exchange, ordered MF Global employees to leave the trading floor and allowed liquidation for customers of the firm.

“Definitely an air of mystery about this one,” noted one former CME floor trader. “When I heard that they were pulling traders out of the pits/denying floor access, I thought they must have defaulted on their clearing obligations or something. None of that happened with Refco; a lot of these floor and upstairs professional guys go through subclearers of MF that they snapped up after Refco went up, so they’ve seen that story before.”

Additionally, the New York Federal Reserve said that MF Global had been suspended from conducting business as a primary dealer.

“MF is one of the more diverse firms – definitely a much wider range of business lines and customers than most other FCMs out there,” another floor trader, who declined to be identified, told Markets Media. “I’m intrigued by Interactive Brokers making a move (whether or not it ends up going through or not) because when I think of IB, I just think of them as an access and technology broker as opposed to a full service firm that provides research, S&T, hedging services, etc., which is what MF was so known for.”

Some brokers have expressed their anger at MF Global’s mismanagement and past acquisitions.

“I feel as though the MF Global debacle seems very surprising, but it is not,” noted yet another futures trade at the CME. “Over the past couple of years, MF has gone through a lot of changes and downgrades. However after their takeover, there was a lot of angst amongst brokers who did not favor the deal. Many floor brokers had already lost their jobs due to downsizing, so the latest news that they can no longer stay solvent only relieves pressure off the other brokers who already knew their days with MF were numbered.”