Stocks powered to new highs on Wall Street, giving the Dow Jones industrials their biggest gain since March and putting them past 24,000 points for the first time.
Other market indicators also reached milestones on Thursday. The Standard & Poor's 500 index, which is widely followed by professional investors, had its biggest monthly gain since February.
Technology stocks were responsible for much of the gain, following a sharp pullback the day before.
Investors welcomed signs that the odds were improving for the Republican-led effort to forge a sweeping tax overhaul bill.
The Standard & Poor's 500 index rose 21 points, or 0.8 percent, to 2,647.
The Dow Jones industrial average gained 331 points, or 1.4 percent, to 24,272. The Nasdaq composite rose 49 points, or 0.7 percent, to 6,873.