Stocks tanked across the US on Thursday with the Dow Jones Industrial Average plunging by more than 7% to its lowest level in five years.

While the Dow Jones fell by 679 points, the Standard and Poor Index also recorded a decline of around 7%. The sell off comes on the one-year anniversary of the closing highs of the Dow Jones and the S&P. ever since Dow closed at a high of 14, 164.53 on October 9 2007, it has lost around 39.4% or 5585 points. The S&P has marked a fall of 41.9% or 655 points since its closing high of 1565.15 last year.

Thursday’s decline came as the Standard & Poor’s rating services put the credit ratings of US auto giants General Motors and Ford under review. While the rating agency brought General Motors and its finance affiliate GM LLC under review to see if its rating should be cut, it also put Ford Motor Co under credit watch negative. However the rating agency clarified that though the companies had enough liquidity for now, the situation may change for the worse, next year.

The warnings by the ratings agency led GM shares to tank by 31% while those of Ford plunged by 22% thus further rattling investors who are already nervous about the impact of credit freeze on the economy.