After a week in which some $2.5 trillion (£1.5 trillion) was wiped off the value of global equities, investors are set to seek further solace from traditional indices, with gold and other safe havens likely to continue their ascent.
Conversely, however, the Government's borrowing costs are expected to hit record lows in the coming weeks, as investors turn to UK government debt as a relative safe haven for their money, amid fears of a new global recession.
With UK government debt still enjoying an AAA rating, the increased demand will push down yields, the implied interest rates, even further.
Many pension funds are obliged to have their money in AAA-rated investments, and other investors will be wary of volatility in the stock market that is expected to ensue.
The 10-year gilt yield already hit a record low of just 2.59pc last week.
The US downgrade is also expected to push the price of gold northwards, despite a slip from its record of $1,684.90 to $1,651.80 an ounce in New York on Friday, as some investors sold the precious metal to cover losses in other markets.
Fitch and Moody's still have AAA ratings on the US, but S&P's move will send shock waves through the markets when trading reopens.
Last week, Wall Street experienced its worst week since September 2008, with the S&P 500 (SNP: ^GSPC - news) falling 7.2pc and the Dow Jones Industrial Average lost 5.2pc. In Britain, the FTSE 100 (Euronext: VFTSE.NX - news) slumped 9.8pc.
Analysts also predict a rush on safe-haven currencies such as the Swiss franc and the Japanese yen, but were divided over the immediate impact on the dollar.
Mansoor Mohi-uddin, head of foreign exchange strategy at UBS (NYSEArca: DJCI - news) , predicted it would remain relatively strong, at least in the first instance, while analysts at Capital Economics said S&P's decision to "finally pull the trigger" would cause the dollar to fall, but that this would be relatively short-lived.