Stocks rose on Tuesday as investors eagerly awaited the results of much-anticipated midterm elections which could have significant implications for investors.
The Dow Jones Industrial Average climbed 173.31 points to 25,635.01, led by gains in IBM and Caterpillar. The gained 0.6 percent to close at 2,755.45 as the industrials and materials sectors outperformed. The Nasdaq Composite advanced 0.6 percent to 7,375.96. All three of the major indexes reached their session highs less than 10 minutes before the close.
Democrats are expected to take control of the House away from Republicans while the GOP maintains a slim majority in the Senate. Stocks have historically done well under a divided government. Since 1928, the S&P 500 has averaged an annual return of 12 percent when Congress is split and Republicans control the White House.
But "this is a very different election and gridlock may not be good" for the market, said Gene Goldman, head of research at Cetera Investment Management. Goldman said the GOP-led government has implemented key policies that are helping the economy grow, and gridlock would slow down similar policies in the future.
Analysts at Bank of America Merrill Lynch said a split Congress is still the most likely outcome, but the probability of a Democratic blue wave in the House "appears to have diminished." The first polls close at 6 p.m. ET.
Whichever way the elections shake out, they could lead Congress to pursue different policy agendas, including lower drug prices, banking regulation and defense spending. The election could also lead to more investigations into President Donald Trump.
The Democrats were leading with a 7 point advantage ahead of the vote, according to an NBC News/Wall Street Journal poll released Sunday. Data released on Monday showed that more than 35 million people have already cast their vote in early voting, indicating a record turnout for the 2018 midterms. In 2014, fewer than 20 million early votes were counted the day prior to the midterms.
"With absolutely nothing on the macro calendar today and the Fed not scheduled to deliver its rate decision until Thursday, investors have the next several hours to focus on the Midterm Elections," said Jeremy Klein, chief market strategist at FBN Securities, in a note.
"Those bullish fear the GOP's losing power in both chambers on Capitol Hill. While stocks would stumble a bit in the immediate aftermath of this unexpected outcome, the dip would present a fortuitous buying opportunity," Klein noted.
Stocks have been volatile lately as worries about the elections, coupled with fears of rising rates and a potential slowdown in earnings growth, have put investors on edge. The Cboe Volatility Index, widely considered the best gauge of fear in the market, is up more than 60 percent since the start of the fourth quarter.
Investors also looked ahead to the Federal Reserve's latest decision on monetary policy, which is scheduled for Thursday. The Fed is largely expected to keep rates unchanged, but investors will pore through the statement for clues about the central bank's December meeting.
—CNBC's Ryan Browne contributed to this report.