Central banks have run during the crisis a wide set of monetary policy interventions using new instruments and techniques to restore the monetary stability and thus re-establish the stability of financial (and banking) systems. We analyze the effect of monetary policy interventions on stock markets in the most advanced monetary areas (Euro area, Japan, U.S., U.K., and Switzerland). We estimate cumulated abnormal returns (CARs) around the announcement of each monetary policy intervention focusing on: 1) interbank credit market; 2) stock markets; and 3) Global Systematically Important Financial Institutions (G-SIFIs). We show that different monetary policy interventions from single central banks have produced a diverse market reaction. Non-conventional measures have been more effective than traditional ones in restoring the stability of financial and banking sectors. Dividing the sample period into three different time intervals, we also show that the impact of expansionary interventions was particularly significant during the subprime crisis, while the effect of restrictive interventions was more relevant during the sovereign debt crisis.