The $40 billion Navy Federal Credit Union, which shelled out more than $217 million in corporate stabilization expenses as of March 31, didn't express much interest in viewing U.S. Central or WesCorp investment summaries, which the NCUA has made available to federally-insured credit unions.

"We could spend a lot of time rehashing history, but what we really need to focus on is how we can minimize this risk in the future," said Dennis Godfrey, chief officer of innovation at the nation's largest credit union.

Navy Fed, along with some other credit unions, has written four tenets they believe will prevent losses in the future, he said. They include requiring only members to capitalize corporates, and matching corporate deposit insurance coverage, investment authority and capital requirements to those allowed or required of natural person credit unions.