Since the Supreme Court's Concepcion and Italian Colors cases, courts have generally enforced arbitration agreement provisions requiring individual, rather than classwide, adjudication. In contrast, the Financial Industry Regulatory Authority (FINRA) ruled otherwise for securities arbitration.
Good lawyering by Pace Law Professor Jill Gross and Cincinnati Law Professor Barbara Black, who argued for this result in their article, Investor Protection Meets the Federal Arbitration Act, 1 Stan. J. Complex Litig. 1 (2012).
As Professor Gross explains at ADR Prof Blog, FINRA held that the Securities Exchange Act constituted a sufficient Congressional command to overcome the FAA’s mandate to courts to enforce arbitration agreements as written. Since the Exchange Act delegated to the SEC, which in turn delegated to FINRA, the authority to regulate broker-dealers’ arbitration agreements for the protection of investors, FINRA’s rules barring class action waivers and mandating that investors be able to bring class claims in court were enforceable [notwithstanding the FAA].