good point however i dont think he can do either without treasury support at a minimum. REceivership is a huge change to our entire housing stucture and economic system millions of americans live off of....Mark calabria can just willy nilly change all of this on his own HAHA doubt it
However, according to the terms of the SPSPAs, the FHFA director cannot end conservatorship without approval from the Treasury Secretary, unless it's because the FHFA director put the companies into receivership.
You can check section 5.3 of that link above for yourself.