Eisman grew up in New York City, where he attended Yeshiva schools. He attended the University of Pennsylvania, graduating magna cum laude in 1984. He then graduated from Harvard Law School with honors.
He has been married to Valerie Feigen since 1989. Valerie was also portrayed in The Big Short under the name Cynthia, by Marisa Tomei.
After the Department of Education took action against for-profit colleges in 2010, the industry retaliated by accusing Eisman of attempting to illegally influence the government and calling for an investigation by the Secretary of Education. The allegations stem from a meeting that Eisman had with Department of Education officials David Bergeron and Robert Shireman, two weeks before delivering his speech at the Ira Sohn Conference. Shireman was in charge of the department's efforts to toughen regulations on for-profit colleges.
In 2012, Eisman founded Emrys Partners with $23 million in seed capital. The fund performed poorly in 2012, returning 3.6% and underperforming the market. It did better in 2013, returning 10.8% but still underperforming the market. In July 2014 he announced that he was shutting down the fund, explaining his decision by stating that "making investment decisions by looking solely at the fundamentals of individual companies is no longer a viable investment philosophy." The fund controlled an estimated $185 million in assets at the time of its dissolution.
In September 2014, Eisman joined Neuberger Berman as a Managing Director and a Portfolio Manager for the Eisman Group within Neuberger Berman’s Private Asset Management division. The group, run by partners including Steve's parents, Elliott and Lillian Eisman, manages portfolios of stocks for wealthy clients.