In 2016, Zions Bancorp came to its lawyers at Sullivan & Cromwell with a problem. The Utah-based bank, with about $66 billion in assets, was among the smallest firms designated as “systemically important,” or too big to fail, under the tougher regulations that followed the 2008 financial crisis. But with that smaller size came no relief from the heightened scrutiny, which bigger banks subject to the same designation could more easily bear.

Rodge Cohen

At Sullivan & Cromwell, a team including one of Wall Street’s most prominent lawyers, H. Rodgin Cohen, had an idea for a new legal strategy to pull Zions out of the Federal Reserve oversight.