U.S. equities closed at record highs on Monday as Wall Street kicked off the fourth quarter on a high note.
The Dow Jones industrial average gained 152.51 points to close at 22,557.60, with Goldman Sachs contributing the most to the gains.
The rose 0.4 percent to 2,529.12, led by gains in health care and financials. Health care was one of the best-performing sectors, rising 0.9 percent, as biotech stocks posted their best day since Aug. 31. Financials rose 0.89 percent and have gained nearly 2 percent in the past month.
"Health care continues to be on fire and financials keep doing well. That's helping out the market today," said Jeremy Klein, chief market strategist at FBN Securities. "It's also the first trading day of the month, which is usually the strongest day of the month for stocks."
General Motors, meanwhile, was among the best-performing S&P components, advancing 4.4 percent after analysts at Deutsche Bank reiterated their buy rating on the stock.
The Nasdaq composite closed 0.3 percent higher at 6,516.72, despite shares of Facebook, Netflix and Alphabet falling.
The Russell 2000 — which tracks small-cap stocks — outperformed, advancing 1.3 percent to a record close of 1,509.47.
The indexes also set intraday records, as they began a historically positive period for stocks. According to CNBC analysis using Kensho, the Dow, S&P and Nasdaq have averaged strong fourth-quarter returns in the past 25 years. Stocks are also building on gains set in the previous quarter.
Stocks wrapped up the third quarter on Friday, with the Dow posting its first eight-quarter winning streak in 20 years. The index rose 4.9 percent last quarter, while the S&P and Nasdaq gained 3.9 percent and 5.8 percent, respectively.
"It's interesting because, as good as the third quarter was, we had a lot of rotation," said Art Hogan, chief market strategist at Wunderlich Securities. "The small and mid-cap indexes did far better than the major averages. That's constructive because it means we can switch spaces and remain at all-time highs."
The Russell 2000 also had a stellar third quarter, advancing 5.3 percent and notching a record high.
"I think the reasons stocks, especially small caps, are doing so well are the economy and hopes of tax reform," said Bruce Bittles, chief investment strategist at Baird.
"The economy is doing well despite the storms," Bittles said. Also, "a lot of folks don't think there will be tax reform but the market thinks there will be. If that happens, it will be a big boost to the economy."
Last week, Republicans unveiled a proposal that would lower the corporate tax rate to 20 percent. The current U.S. corporate tax rate sits at 35 percent.
Tax-reform expectations have been a key catalyst for stocks since President Donald Trump's election, along with hopes of deregulation.
In economic news, the ISM manufacturing index rose to 60.8 in September, the highest read since May 2004. Dallas Federal Reserve President Robert Kaplan is also scheduled to speak at 2 p.m. in New York.
Elsewhere, casino stocks fell after the Las Vegas . fell as much as 2.1 percent before closing 1.3 percent higher.
and fell 1.2 percent and 5.6 percent, respectively. The broader stock market remained higher as details of the shooting were released.