Crude oil prices briefly hit the $100-a-barrel mark and gold prices jumped to an all-time high as investors poured money into commodities on Wednesday amid deepening fears about the weakness of the US dollar.

The oil price rally soured the first stock trading day of the year, with the Dow Jones Industrial Average closing 1.7 per cent lower, its worst start since a slide of 1.9 per cent on the first day of trading in 1983.