POG comment from USA Fund, page-3

"When a stock/Index/Commodity doesn't react as events indicate it should, it's a powerful contrarian signal."

Not verbatim but a maxim from one of the uber traders interviewed in Market Wizards.

For mine, gold told us something when it fell even while the market was tanking.

Mind you it might have been telling us that it was being sold down to fund an orchestrated push into equities. However I suspect it was saying that it's not the currency of last resort, just heavy shiny stuff that people wear around their necks.