The announcement last Wednesday of coordinated action by the Fed, ECB and other central banks to boost global dollar liquidity certainly had a big impact on financial markets. The announced changes themselves were, in all honesty, fairly modest. Accordingly, it appears that the markets were reacting more to the symbolism of the announcement: interpreting it to mean that the world's central banks will do everything possible to prevent another global credit crunch and/or the Fed will also act to boost the US economy, presumably using more quantitative easing.