That, says Brooks, will be the "real test of market sentiment".

"It seems to be driven by market sentiment, which is often more than the reality."

And others argue that over a relatively limited period of time, changes in short interest may say nothing about market sentiment at all.

You could say this is just a case of market sentiment shifting.

The most positive factor they cite is the current highly negative market sentiment.

They find the impact of changes in market sentiment tends to be limited to the original region.

And it usually takes about two rate cuts to turn market sentiment around.

"The impact on market sentiment if people thought he was really pulling out would be devastating."

"You have to be able to capture market sentiment," he said.

But even observing magazine covers can give a feel for whether the general market sentiment is too strong in one direction or other.