The biggest losers in MF Global’s bankruptcy by Nin-Hai Tseng @FortuneMagazine November 1, 2011, 5:55 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Jon Corzine, the biggest loser? FORTUNE — MF Global’s bankruptcy may be the biggest failure of a U.S. financial firm since the collapse of Lehman Brothers in 2008, but its demise has not been nearly as catastrophic on financial markets — at least not yet. MF Global’s decision to file for bankruptcy protection Monday triggered a frenzy of activity on the Chicago Mercantile Exchange, as firms whose trades are cleared by the broker-dealer were unable to execute orders, according to the Financial Times . But unlike the infamous Lehman moment, there were limited signs of strains on liquidity and no major disruption in the funding markets. Sure, the Dow tumbled Monday and is falling again today, but this reaction is tame compared to the panic after Lehman’s fall and AIG’s near collapse. Nevertheless, MF Global’s MF downfall is Wall Street’s first casualty from the ongoing European debt crisis, so tensions are understandably high. Major rating agencies thought the firm had taken on too much risk with its $6.3 billion bet on European sovereign debt. And in a series of credit downgrades, Moody’s MCO , Standard & Poor’s and Fitch downgraded the firm to “junk” status. Most of us on Main Street won’t feel an immediate impact from MF Global’s demise, but needless to say, several stakeholders won’t be walking away unscathed: Preferred stockholders Private equity investor J. Christopher Flowers may have placed former New Jersey Governor Jon Corzine as MF Global’s top executive (they were both formerly executives at Goldman Sachs GS ), but the financier who was a significant investor of the bankrupt firm through his firm J.C. Flowers & Co. may see millions in losses. It has been widely reported that the private equity firm paid $87.4 million three years ago for MF Global preferred stock. Over the last three years, the dividends paid handsomely – it reportedly yielded J.C. Flowers $39.6 million. But with the collapse of MF Global, the fund is expected to mark the investment down to nothing and suffer a net loss of $47.8 million. Common shareholders And of course, the firm’s biggest common shareholders could lose millions. Here’s a list of some of the bigger ones and their respective stakes in the firm according to recent filings: Pyramis Global Advisors LLC, owning 8.44% common shares; RS Investments, 7.81% (Update: An RS Investments spokeswoman told Fortune the company sold its shares of MF Global on October 26 ahead of the firm’s file for bankruptcy protection); Fine Capital Partners LP, 7.37%; Cadian Capital Management LLC, 6.17%; TIAA-CREF, 5.77%; Advisory Research Inc., 5.54%; Dimensional Fund Advisors LP, 5.41%; Rydex Security Global Investors LLC, 5.13%. Unsecured creditors In a bankruptcy, unsecured creditors get repaid after secured lenders. According to MF Global’s bankruptcy filing, some of the firm’s biggest unsecured lenders include: JP Morgan Chase JPM , a trustee with a claim of $1.02 billion in bonds; Headstrong Services LL with a claim of $3.9 million; and Comcast Corp. CMCSA ’s CNBC with a claim of $845,397 (unpaid ad sales). MF Global’s star bankers When Corzine took over as MF Global’s CEO in March 2010, the firm was one of the few on Wall Street adding staff as banks worldwide announced hundreds of thousands of layoffs amid the financial crisis. Corzine, who helped run Goldman Sachs from 1994 to 1999, hired 800 employees in efforts to turn the broker-dealer into an investment bank. As Bloomberg reports, recruits included: Michael Stockman, UBS AG’s former chief risk officer for the Americas, Richard Moore, once Citigroup Inc C ’s head of European fixed-income, and Jon Bass, also previously of UBS and a member of the investment bank’s board. It’s anyone’s guess where they might end up, but for now at least, many of them will likely join the millions already in the job market. Jon Corzine himself Corzine was widely viewed as attempting to revive his Wall Street career by taking the helm at MF Global. Coming off a stint in public service, the former Goldman Sachs CEO tried to makeover MF Global into something bigger by taking on risky trades. Whatever his intentions, the firm’s meltdown seems to be testing his rep on Wall Street. Corzine had a long business relationship with Flowers, dating back to their days at Goldman decades ago. He is an operating partner at Flowers’ private equity firm, although many reportedly expect him to be removed from his position soon. It also remains to be seen if Corzine will be able to work his way back into the graces of Wall Street. And we know he won’t end up poor, even if his $12 million severance payment is rescinded by the bankruptcy court. But for now, as federal regulators investigate hundreds of millions of dollars in customer money missing from MF Global in recent days, his reputation on the Street may be at stake. Update: An earlier version of this story misstated that Corzine no longer worked for J.C. Flowers & Co. At the time of posting, he was still employed at the private equity firm, although he was expected to be removed from his role soon.