The Dow Jones industrial average surged 331.67 points to close above 24,000 for the first time, with United Technologies leading advancers on the 30-stock index.
The S&P 500 advanced 0.8 percent to close at 2,647.58 — an all-time high — with industrials and information technology among the best-performing sectors. L Brands and Kroger were the best-performing stocks in the index.
The Nasdaq composite rose 0.7 percent to close at 6,873.97, rebounding from a 2 percent decline in the previous session. Tech giants like Facebook, Amazon, and Apple all traded higher.
"This tax-reform bill is not just about" potentially lowering taxes said JJ Kinahan, chief market strategist at TD Ameritrade. "It's also a psychological factor that Congress can get something done. That would be a positive."
Sen. John McCain said Thursday he would support the bill, making it more likely that the GOP-led Senate will pass its bill. The Senate is expected to vote later on Thursday. If the upper chamber's bill passes, the House and Senate would have to work on a new bill they can send to President Donald Trump.