In testimony before the Senate Banking Committee on Wednesday, JPMorgan Chase CEO Jamie Dimon will say that his traders did not understand the risks they took that led to more than $2 billion in losses but that the credit derivative bets in question are an anomaly in the firm’s overall record.

According to prepared remarks, Dimon will highlight the positive work JPMorgan does, such as making $62 billion of credit available to consumers in the first quarter of this year. But he will also apologize for the series of oversights that allowed the bank’s chief investment office to engage in trading that was not vetted or tracked properly.

“We will not make light of these losses, but they should be put into perspective. We will lose some of our shareholders’ money — and for that, we feel terrible — but no client, customer or taxpayer money was impacted by this incident,” Dimon will tell the panel. “This portfolio morphed into something that, rather than protect the firm, created new and potentially larger risks. As a result, we have let a lot of people down, and we are sorry for it.”

In his play-by-play of what went wrong, Dimon explains that the bank’s synthetic credit portfolio “was poorly conceived.”

“The strategy was not carefully analyzed or subjected to rigorous stress testing within CIO and was not reviewed outside CIO,” Dimon will say. “In hindsight, CIO’s traders did not have the requisite understanding of the risks they took. When the positions began to experience losses in March and early April, they incorrectly concluded that those losses were the result of anomalous and temporary market movements, and therefore were likely to reverse themselves.”

Despite a rigorous defense of JPMorgan’s operation that Dimon is prepared to make before the committee, the panel’s members are likely to fire off a litany of tough questions, both to grill a CEO once revered by the Obama administration but also to prove they are serious about a buzzworthy current event. Hearings on banking fails tend to provide some of the best Congressional cinema around, with a 2010 session on Goldman Sachs resulting in Members repeating profanities contained in emails between employees of the banking giant.

The banking hearing Wednesday is just one in a series investigating the Dodd-Frank Wall Street reform law, its ongoing implementation and its effects.

Dimon is slated to testify before the House Financial Services Committee later this month.