The S&P 500, a barometer for the top 500 US stocks on the New York Stock Exchange, rose 0.5 percent, ending at 3,720, after setting an earlier all-time high at 3,724.
The Nasdaq Composite Index, which counts on the performance of US tech stock giants such as Facebook, Apple, Amazon, Netflix and Google, gained 0.8 percent to conclude at a record high of 12,765.
The Dow Jones Industrial Average, Wall Street’s broadest stock gauge, edged up 0.5 percent to close at 30,302, after a historic 30,324 peak.
Stocks rose on signs that US lawmakers were closing in on a second COVID-19 economic stimulus, following the $3 trillion package passed by Congress in March. Congressional leaders have all indicated that a deal is imminent.
Equity markets were also supported by the Federal Reserve's announcement on Wednesday that it will buy at least $80 billion per month of Treasury securities and $40 billion per month of agency mortgage-backed securities in a bid to provide maximum employment and price stability.
