Almost a decade after the financial crisis of 2008, the individuals and institutions responsible for the subprime mortgage crisis that created the worst financial disaster since the Great Depression have paid almost no price for it.

Some fines were paid by banks to the government, a handful of bankers ended up in prison, but few investors were able to recover the money lost by the banks and their investment companies. Now, as Senator Al Franken has noted, Trump has filled his administration with billionaires who played roles in nearly wrecking the world’s economy.

On Monday, a trial begins before Justice Saliann Scarpulla in the Manhattan Supreme Court, to see if one bank, JPMorgan Chase, can be held accountable for the loss one victim suffered. The victim is Ambac Assurance UK, a subsidiary of New York-based Ambac Financial Group; Ambac is a guarantor, meaning the company pays principal and interest on securities if the issuer of the securities defaults. In May 2006, Ballantyne Re, a financial holding company created by Scottish Re, entered into an agreement with JPMorgan Investment Management (JPMIM), a division of JPMorgan Chase, to invest $1.65 billion. The investment, subject to an agreement that spelled out investing guidelines, was guaranteed by Ambac.

The contract required JPMIM to pursue “reasonable income while providing a high level of safety of capital.” It also required JPMIM to adhere to a law called the Delaware Insurance Code, which stipulates that an insurance company is not allowed to invest more than 50 percent of its assets in mortgage-backed securities. But, right away, according to court documents, JPMIM invested almost the entire $1.65 billion—about 90 percent—in mortgage-backed securities.

By July 2007, the portfolio had started to lose money. By Dec. 28 of that year, the losses had grown so significantly the investment agreement was altered to require Ballantyne to approve all future investments. Still, the hemorrhaging continued until October 2008 when Ballantyne terminated the agreement, yet not before, in just 30 months, JPMIM had lost $1 billion for Ballantyne—money Ambac was required to cover since the company guaranteed the investment. But Ambac balked at paying up because it believed JPMIM’s actions had led to the loss. So, on May 4, 2009, Ambac filed a lawsuit arguing that because JPMIM acted with gross negligence and blatant disregard for the investment agreement JPMorgan should have to repay the $1 billion—not Ambac.

What happened that led to such a staggering loss? Most damaging was JPMIM’s failure to move any of the principal in the portfolio out of high-risk securities even when it became clear the subprime mortgage market was declining drastically—a development the higher-ups at JPMorgan had plainly identified.

In an interview for the Sept. 2, 2008 issue of Fortune, Jamie Dimon, the CEO of JPMorgan Chase, revealed that as early as October 2006 he concluded that “this stuff”—subprime mortgage-backed securities—“could go up in smoke.” He admitted he was so worried he ordered his head of securitized products “to sell a lot of our positions.” They did. A subsequent court document notes that in late 2006 JPMorgan, to quote from a Fortune article cited in the judge’s decision, “started slashing its holdings of subprime debt” and “sold more than $12 billion in subprime mortgages that it had originated.”

Dimon later said at a financial conference that JPMorgan loan defaults were increasing “a little bit,” but, if the economy goes into recession, “home equity is subject to deterioration.” Even with this present danger, even with JPMorgan selling off its own high-risk mortgage-backed assets, the portfolio manager for the Ballantyne account, Mark Stancher, continued to hold these risky securities. For his part, Stancher contends he discussed his investment strategy with his client.

“Inexplicably,” says Michael Allen, an attorney for Ambac, “JPMorgan assigned a portfolio manager to the account who created portfolios that were highly concentrated in a single subprime vintage and then ignored them. The markets changed radically. JPMorgan protected itself. It did nothing for its client. Not a single change was made.” Attorneys for JPMorgan Chase declined to comment.

Ambac’s description of Stancher’s actions is reflected in court documents. “[He]… testified [in his deposition],” Judge Scarpulla wrote in an opinion, “that he did not recall whether he sought any legal advice on whether the investments complied with the Delaware Insurance Code; or whether JPMIM undertook any steps to track the investment portfolio’s compliance with the provision of the Delaware Insurance Code.” Moreover, the judge continued, Stancher’s colleagues charged with helping manage the account were not even aware the account was required to comply with the Delaware code—a fact that should have been called to their attention by Stancher.

Now a Manhattan judge will determine if JPMorgan is guilty of gross negligence and responsible for paying the $1 billion it lost for Ballantyne. A similar case, brought by Orkney Re against JPMorgan Chase, will be heard simultaneously by the same judge. Earlier, in 2005, JPMorgan agreed to pay $388 million to settle a lawsuit brought against the bank by the Fort Worth Employees’ Retirement Fund for mishandling investments during the crisis. But few companies have sought, much less received, retribution for the losses they suffered because of actions the banks took—or failed to take. Stay tuned.