On April 3rd, the Federal Reserve Board approved a final rule that establishes the requirements for determining when a company is "predominantly engaged in financial activities." The requirements will be used by the Financial Stability Oversight Council when it considers the potential designation of a nonbank financial company for consolidated supervision by the Federal Reserve. The final rule also defines the terms "significant nonbank financial company" and "significant bank holding company." The final rule will become effective on May 6, 2013. Federal Reserve Board Press Release. The Washington Post noted the implications of the new rule, including the companies that are likely to be named "significant nonbank financial companies." Implications.