An antitrust suit filed in the Southern District Thursday seeks to push major financial institutions toward greater transparency in the credit default swap market, potentially opening the door to more investor litigation in the space.

The parent company to a small New York-based exchange, Tera­Exchange, alleges that Tera­Exchange has been frozen out of the CDS market by the banks—noting that JPMorgan Chase, Bank of America, and Citigroup alone control 40 percent of the domestic market. The plaintiffs claim that those three banks, along with 10 other named financial institutions, essentially corner 95 percent of the CDS market.