In 2010, the S.E.C. secured $550 million from Goldman Sachs. In that case, the agency focused on a single mortgage security created in 2007, just as fissures spread through the housing market. Goldman allowed a hedge fund manager, the S.E.C. claimed, to help construct the security, then bet against it, but never alerted investors.

The S.E.C.’s investigation into JPMorgan included creating troubled securities itself, as well as misleading investors through its Bear Stearns unit, the troubled investment bank it purchased at the urging of the federal government in 2008.

In a December 2006 sale of $1.8 billion of mortgage-backed securities, JPMorgan played down delinquency rates of the mortgages used as collateral in the securities, according to the S.E.C. Despite assurances by JPMorgan that only 0.04 percent of the loans were more than 30 days delinquent, roughly 7 percent of the loans were troubled, the agency said. While the bank reaped $2.7 million as part of the deal, investors didn’t fare as well, losing at least $37 million, according to the S.E.C.

The S.E.C. also faulted Bear Stearns for pocketing compensation it received from mortgage lenders for shoddy loans that the firm had purchased to package into mortgage securities. Bear Stearns, the agency claimed, never passed that money on to investors in the securities. As a result, Bear Stearns received $137.8 million, the agency said.

Credit Suisse was also accused of keeping roughly $55.7 million in such payments from investors. The Swiss bank was also faulted by the agency for misstating when it would buy back mortgages if homeowners fell behind on their payments, as part of $1.9 billion in securities it underwrote in 2006.