Chicago activity index stronger but revisions disappoint

One of the better predictors of the US economy's fortunes has come in strong.

The Chicago Fed national activity index is designed to gauge economic activity in the surrounding area. It rose from -0.43 (revised from -0.15) to 0.14 in August.

So a nice number, much higher than expectations of a rise to 0.05, but that huge downward revision is pretty alarming.