Whatever happens the Fed’s foot is not far from the gas pedal right now.
Inflation low they will error to the side of pushing further on the gas.
Interest rates are already low. There are plenty of buyers for debt (bonds). The Fed can start more QE, but after 3.5 rounds of QE, will it have the desired psychological effect the 4.5th time? It would be interesting if the Fed started QE4 and the markets unraveled anyway.