Research ex post facto law as applied to civil and administrative law. Everything except for the punishment/criminalization can be applied retroactively.
Retroactive application in regards to civil and administrative law HAS been argued in a court of law and been found legal.
Dodd-Frank CAN be applied retroactively with regards to FDIC seizure in 2008 and subsequent actions regarding seized assets. Criminalizing acts and punishment/sanctions portion of Dodd-Frank CANNOT be applied retroactively.
Dodd-Frank is a broad bill that also contains Administrative law.