The FSOC—a council of federal financial regulators chaired by the Treasury secretary—was in many ways the heart of Dodd-Frank. The legislation gave the council two extraordinary powers. The first, which the Obama administration used, was to designate large nonbank financial firms for enhanced supervision by the Federal Reserve if the FSOC concluded that a firm’s failure could threaten U.S. financial stability. The second, which even the Obama administration apparently considered too dangerous to use, was to designate any financial company, of any size, for enhanced Fed supervision if its “nature, scope, size, scale, concentration, interconnectedness, or mix of . . . activities” could threaten U.S. financial stability. That became known as the “activities” authority.

https://www.wsj.com/articles/the-trump-treasurys-disturbing-regulatory-turn-1512601948