The Dow Jones index broke through the 15,000 point threshold for the first time ever on Tuesday.
Big moves in the technology and materials sectors helped the S&P 500 close at its highest ever level on Monday.
Global markets soared on Wednesday after the US Federal Reserve inadvertently released minutes from its latest policy meeting five hours earlier than planned.
The largest equity markets in the US have reached new record highs after an uptick in manufacturing data boosted investor sentiment.
The Dow Jones Industrial Average - one of the two most quoted indices in the US - has hit a record high above 14,200 points, surpassing its 2007 peak.
US and Asian equity markets rallied overnight as talk of US politicians reaching a deal to avert the fiscal cliff helped sooth investor worries.
US indices slumped overnight as prospect of politicians at loggerheads over the fiscal cliff continued to worry investors.
The Dow Jones Industrial Average closed at a four-year high overnight Tuesday as investors flocked to US stocks amid the resurgence in the country's economy.
The Dow Jones Industrial Average closed at a four-year high last night as investors flock to US stocks amid the resurgence in the country's economy.
The FTSE 100 has traded flat at the open after gaining 1.9% yesterday - a day which also saw leading US indices reach their highest levels in four years.