The market's stance heading into the new week is one of caution. Market analysts and traders are trying to determine whether Standard & Poor's downgrade of the U.S. Government's credit rating from AAA to AA+ was an aberration, or whether it reflects the shape of fiscal things to come.

"The [S&P] downgrade was expected," Peter Cardillo, chief market economist at Rockwell Global Capital, told Dow Jones Monday. "As the first-ever [U.S. debt downgrade] announcement, it was taken as a shock, but I think it was pretty much priced into the marketplace."

"Whether or not investors continue to choose to lower the risk, I think that's yet to be seen and I think the real basis for this huge decline has a lot to do with hedge-fund selling, which feeds on itself," Cardillo added.

Another Downgrade By S&P?

Earlier Sunday, S&P's managing director John Chambers indicted that the U.S. was at risk for a further rating downgrade.

Moody's added another semi-data point to the downgrade-is-valid argument when it announcedMonday it could downgrade the U.S. before 2013 if the nation's fiscal or economic outlook weakens significantly.

Moody's said the United States "continues to exhibit the characteristics compatible with a Aaa rating" despite the expected further deterioration in the government's debt metrics in the next few years.

Meanwhile, the talk in Washington was that the S&P downgrade would likely increase pressure on the new Congressional "supercommittee" to end ideological differences and political posturing to quickly devise a substantive deficit reduction package that goes beyond the $1.5 trillion called for in the recently-passed U.S. debt deal, which also raised the nation's debt ceiling.

"I think this is one of the most telling, important moments in our country's history right now," Senator John Kerry, Democrat of Massachusetts, said Sunday on the NBC program "Meet the Press." He added: "This poses a set of choices not just about a recession. It's about a financial crisis and the structure of our economy, which really has been misallocating capital."

However, the above is not to say that the U.S. Treasury Department has changed its stance regarding S&P's controversial decision: ithaven't.

The U.S. Treasury Department believes S&P erred by at least $2 trillion in its deficit projection, with the department adding that U.S. bonds were as safe now as they were last week. "The judgment by S&P changed nothing, added nothing to what people know about this country," U.S. Treasury Secretary Timothy Geithern said, marketwatch.com reported.

Market/Economic Analysis: The market is likely to spend the next two or three days digesting the S&P decision, and the rating agency's stunning downgrade is by no means an introvertibly correct decision. Numerous S&P assumptions are being challlenged, and one can not rule-out a Congressional investigation of S&P, and the sovereign debt ratings process, in the months ahead.

Hence, the word to the wise for investors for the early part of the week is that old Wall Street axiom during uncertainty, "Don't just do something, stand there."