I think what you ' re essentially stating , knowingly or not , is that regulations don ' t matter as it ' s up to banks to follow and just controlling the size to limit the failure is the most important thing . I sort of agree , but to say banks willy nilly choose which rules to follow . I go back to my point that the amount of people internally audit , compliance , regulation that police these things these days is incredible . It is waaaay harder to skirt rules these days and way more punitive to do so . Sure , things will still go wrong , but just because people still rob homes doesn ' t mean the laws against burglary aren ' t effective or meaningful . It ' s a fine fine line between legitimate profitdriven speculation and reckless speculation . The two aren ' t mutually exclusive . The point is that bank ' s shouldn ' t be speculating prop trading at all per Volcker . I think what you might be meaning or should be is that there ' s a fine line between legitimate client centric business and prop tradingspeculation . This is true and Volcker rule is likely as far as regulations will get in this . Of course Volcker itself would not have mitigated the crisis . It was a storm of oversights and poor calculations on many levels . No single regulation would have done anything .