As one of the only banks that remained profitable during the financial crisis of 2008, JPMorgan was considered by many to be the sturdiest bank in the world.

But in the wake of news that the bank had lost $2 billion due to a trading mistake, it now appears that CEO Jamie Dimon was over-confident when he pointed to the strength of his institution as an argument for limited regulation. Over the past few years, Dimon has railed against new rules aimed at protecting the American economy from another meltdown, saying they constitute an excessive regulatory response.

Dimon, who has earned a reputation for brash talk, once called international bank rules "anti-American" and said public criticism of bankers is "a form of discrimination." Dimon has referred to the Dodd-Frank Financial Reform Act as "Dodd Frankenstein."

When a team of reporters led by Stephanie Ruhle at Bloomberg revealed that a JPMorgan trader working from London was placing bets so large they were distorting prices, Dimon called those concerns "a complete tempest in a teapot."

Just two days before the news broke of JPMorgan's massive loss, Dimon lamented to NBC's David Gregory that the "anti-business behavior" of Democrats and the "attacks on work ethic and successful people" were disturbing and "counter-productive."

In an emergency conference call on Thursday afternoon, Dimon reiterated his opposition to the Volcker rule, a Dodd-Frank provision that bars banks from placing speculative bets with their own money and might have restricted the trade at issue.

He did, however, admit that the loss played "right into the hands of a bunch of pundits out there."

Although he acknowledged that the losses were not good, Dimon has maintained that his business will always make mistakes.

One of the few signs of contrition from Dimon came during a follow-up interview with NBC that aired Sunday, when he said he had been "dead wrong" to laugh off concerns about the size of trades being made from the London office.