MARK LENNIHAN / AP

Related Dimon Fortress Breached as Push From Hedges to Bets Blows Up Bloomberg

JPMorgan’s $2 billion bungled trade has severely damaged the reputation of its CEO Jamie Dimon and vaporized nearly $20 billion in shareholder value. But will it lead to the kind of enhanced Wall Street regulation many experts have called for since the financial crisis? Pro-reform forces are already seizing the debacle as proof that even stronger reforms are needed. On Tuesday, top regulators crafting the Volcker Rule, which is supposed to prevent Wall Street banks from making firm-risking bets, will meet in New York. JPMorgan is on the agenda, according to Reuters. Some experts, including a prominent Federal Reserve official, believe that Volcker doesn’t go far enough, and have called for the banks to be split up and reduced in size, so that if one blows up, it won’t pose such a risk to the financial system that the government is forced to bail it out.

Last Thursday, Dimon disclosed the $2 billion loss during a hastily-convened conference call that stunned Wall Street. Dimon said the firm’s in-house investment office had engineered a portfolio of complex financial derivatives as a “hedge” to balance out potential losses elsewhere on its books. As the markets turned against JPMorgan, the portfolio began to experience huge losses — $100 million per day and more — spinning beyond the control of the bank’s risk managers. And it’s not over: the portfolio has worsened since last week’s disclosure, according to Bloomberg, and Dimon said the bank could face $1 billion in further losses. The Securities and Exchange Commission is investigating the breakdown, which caused JPMorgan shares to plunge 10% last Friday. The bank’s stock price tumbled an additional 3% in trading Monday.

Dimon has been Wall Street’s foremost opponent of the Volcker Rule, a central part of the Dodd-Frank financial package aimed at preventing banks that can collect government-insured deposits from making risky, so-call “proprietary” bets. It’s not hard to see why. The JPMorgan unit that made the trades, the chief investment office, was placing bets using “excess” customer deposits that the bank had not loaned. And it was growing ever-more successful, earning billions in profit in recent years. Thanks to vigorous lobbying by JPMorgan ($7.6 million last year) and others, the Volcker Rule, which is still being crafted ahead of its scheduled July 21 launch date, includes a loophole that allows the banks to make “hedge” trades, which are supposed to reduce risk elsewhere on their books — not blow up into $2 billion losses.

(More: ‘Whale’ Fail: JPMorgan’s $2 Billion Blunder Tied to London Trader)

On the conference call, Dimon suggested the trades didn’t violate the Volcker Rule because they were hedges, a view apparently shared by the Comptroller of the Currency Office, the national banks regulator, according to Sen. Bob Corker, the Tennessee Republican who has called for a hearing over JPMorgan’s loss. The Volcker Rule, as currently written, allows “risk-mitigating hedging activities in connection with and related to individual or aggregated positions, contracts, or other holdings of a banking entity that are designed to reduce the specific risks to the banking entity.” But late Monday, in an odd reversal, The New York Times cited a “JPMorgan official” as saying the bank now believed that the trades “would not have been allowed under the Volcker Rule as it was intended.”

Indeed, it appears the JPMorgan traders were going much further than hedging, according to Bloomberg, which reported Monday that Dimon himself had pushed to transform the “once conservative” chief investment office into a risk-hungry profit center. Bloomberg also reported that earlier this year, the now-ousted Drew and five JPMorgan colleagues met with Fed staff and recommended that the division’s trades “not be included as prohibited proprietary trading.”

JPMorgan’s loss could add weight to calls made by Dallas Federal Reserve Bank President Richard Fisher, who has urged that the “too big to fail” banks be broken up. In March, one of Fisher’s colleagues, Harvey Rosenblum, the head of the Dallas Fed’s research department, wrote a report introduced and endorsed by Fisher that brands the biggest banks as “a hindrance to full economic recovery and to the very ideal of American capitalism.”

(More: Top JPMorgan Exec Out Over $2B Blunder as CEO Dimon Faces Heat)

On Monday, Massachusetts Senate candidate Elizabeth Warren called for a new Glass-Steagall Act, the Depression-era law that separated commercial and investment banks. For decades following the law, which followed the stock market crash of 1929, financial panics were rare, as New York Times columnist and Princeton economist Paul Krugman pointed out Monday. “This system gave us half a century of relative financial stability,” Krugman wrote. “Eventually, however, the lessons of history were forgotten. New forms of banking without government guarantees proliferated, while both conventional and newfangled banks were allowed to take on ever-greater risks. Sure enough, we eventually suffered the 21st-century version of a Gilded Age banking panic, with terrible consequences.”

Warren urged supporters to press Congress to pass a new Glass-Steagall law that would separate “high-risk investment banks” from more traditional banking. “It would allow Wall Street to take risks, but not by dipping into the life savings and retirement accounts of regular people,” Warren said. “And by making banks smaller, a new Glass-Steagall could also help put an end to banks that are ‘too big to fail’ — further avoiding costly taxpayer bailouts.” Warren also called for Dimon to step down from the board of the New York Fed, calling his presence there a conflict of interest.

So will JPMorgan’s loss end “too big to fail” once and for all? If recent history is any guide, it’s unlikely. If the global financial meltdown didn’t end “too big to fail,” it’s hard to imagine a comparatively minor $2 billion loss doing so. And Wall Street lobbyists are already trying to contain the damage in Washington. At a minimum, though, the bank’s debacle could make for some interesting hearings on Capitol Hill. In a statement emailed to TIME by the Senate Banking Committee, Senator Tim Johnson, a South Dakota Democrat and the panel’s chairman, said hearings on Wall Street reform would take place “over the next few weeks.” Johnson said the hearings will include witnesses from all of the major financial industry regulators, and will focus on derivatives oversight and enhanced banking supervision. He said JPMorgan’s $2 billion trading loss would be discussed.

LIST: Top 10 Biggest Trading Losses in History