The 2007-2009 financial crisis highlighted the problem of “too big to fail” financial  institutions—the concept that the failure of large financial firms could trigger financial  instability, which in several cases prompted extraordinary federal assistance to prevent their  failure. One pillar of the 2010 Dodd-Frank Act’s (P.L. 111-203) response to addressing financial  stability and ending too big to fail was the creation of an enhanced prudential regulatory regime  for large banks. (The act also envisions the regulation of systemically important nonbank  financial firms under this regime, but that part of the regime is effectively defunct.)