Wall Street’s biggest banks have reached a $1.87 billion settlement in federal court over allegations they worked together to rig the market for credit default swaps. “We think it’s historic,” an attorney for the investors that brought the challenge told Reuters. “It’s one of the largest antitrust class-action settlements, and an extraordinary result for the class.” Among the investors are the Los Angeles County Employees Retirement Association, hedge funds, university endowments  and others

The list of defendants includes some of the biggest names on Wall Street: Bank of America Corp., Barclays PLC, BNP Paribas SA, Citigroup Inc., Credit Suisse Group AG, Deutsche Bank AG, Goldman Sachs Group Inc., HSBC Holdings PLC, JPMorgan Chase & Co., Morgan Stanley, Royal Bank of Scotland Group PLC and UBS AG.

Investors had argued the banks conspired to fix prices and limit competition in the trading of credit default swaps, restricting the flow of market information in violation of U.S. antitrust laws. Credit default swaps are contracts that authorize investors to buy protection to hedge against the risk that debt issuers will fail to meet their payment obligations. Although the contracts are traded fairly frequently, the $16 trillion market is opaque.

The lawsuit also named as defendants the International Swaps and Derivatives Association (ISDA), an industry trade group, and Markit Group Ltd., a market-information provider financed by the banks.

The plaintiffs argued that as a consequence of the price-fixing, they paid unfair prices on trades of credit default swaps from late 2008 to 2013. They claimed the banks maintained exclusive access to price data and actively sought to maintain their monopoly on information. As a result, investors said they did not know how much a broker was profiting from a transaction.

Both the U.S. Justice Department and the European Union’s antitrust arm had probed the big banks on the subject, according to Bloomberg News. The Justice Department reportedly closed its investigation in October 2013, but the EU probe remains open.

Investors said parties will hammer out the details of the settlement in the coming weeks. Banks have declined to comment thus far, but the ISDA released a statement: “We are pleased the matter is close to resolution. ISDA remains committed to further developing [the credit default swap] market structure to ensure the market functions safely and efficiently.”