Vanguard warns investors

Vanguard Group is waving the yellow "Caution" flag at investors who think the stock market has come back for good and last year's collapse was just an aberration.

"Markets have 'come a long way in a hurry,' as the saying goes," the Malvern mutual fund giant tells investors in a note here. The S&P and other U.S. and foreign index funds are up robustly; mining and junk-bond funds are up even more. But Vanguard Capital Value and other high-flying funds "can be properly considered aggressive, and all encompass significant risks... 'Hot' markets eventually cool."

Separately, Vanguard investment chief Gus Sauter drop-kicks his personal crystal ball: "No one knows whether we're due for a correction, or if we're witnessing the start of a really sustained bull market.

"It wouldn't be at all unusual for the market to pull back from its recent gains over the next few weeks or even months, as that often happens after a sudden rise in prices.

"But it also wouldn't be surprising if that were a temporary correction that's followed in very short order by another bull market..."