Boy, that's a good question...

Overnight, Japan injected $8.5 billion, Australia injected $4.2 billion, the ECB injected another $61 billion (on top of yesterday $130 billion) and the U.S Fed tossed another $19 billion into the system (on top of yesterday's $24 billion). That's a total of ~$250 billion injected by Central Banks in 24 hours.

Again, with the global equity markets UP on the year, the question is again begged:

What is the looming shoe that they see?