Quote from ajcrshr:
Some, like David Rosenberg, think the Fed will come out with a big surprise tomorrow. Everyone expects operation twist which would not really be very impactful. If they decide to surprise with something big, they would have been discussing it with the primary dealers. Some may be buying in anticipation of a surprise which would lead to a sell off if only OT was announced Wed. There is a chance, however, the PD's know something concrete about a surprise we don't.
http://www.newyorkfed.org/markets/pridealers_current.html