The market wants the Fed to say something – say ANYTHING – that hints at, signals or implicitly promises more action on the stimulus front. This is because the first few rounds have been so successful.
If Bernanke and Co wait and hold off, they risk the charge of politicization by acting in the future (closer to the election). If they act now, they spend their bullets ahead of whatever the fuck happens with Europe this September.
In other words, the infantile traders who now use the markets as a mechanism to throw temper tantrums may want action now, but the decision is not so easy for