The US credit rating was downgraded to AA+ from AAA by Standard and Poor’s on 5 August 2011. This can increase the cost of borrowing for the US and setting off more panic selling in stock markets. This is the first time that Standard and Poor issued a negative outlook on the US government since it started rating the credit-worthiness of railroad bonds in 1860.
The rating may be cut to AA within two years if spending reductions are lower than agreed to, interest rates increase or new fiscal pressures result in higher government debt.