The last time oil plummeted 30% in less than five months was in March-June 2012, coinciding with a period of a rising US dollar and the most recent episode of the Eurozone debt crisis. Three months later, the ECB announced its readiness to do QE, and three months after that the Fed started QE3. Today, oil prices are 30% lower than five months ago, and calls for ECB QE are louder than ever, while the Fed has just ended its own stimulus measures. Will OPEC need its own QE? Full charts & analysis.