U.S. stocks closed mixed on Monday as investors mainly focused on energy stocks after Hurricane Harvey wreaked havoc in the United States over the weekend.

The Dow Jones Industrial Average lost 5.27 points, or 0.02 percent, to 21,808.40. The S&P 500 gained 1.19 points, or 0.05 percent, to 2,444.24. The Nasdaq Composite Index was up 17.37 points, or 0.28 percent, to 6,283.02.

Now tropical storm Harvey ravaged Houston and other parts of Texas over the weekend. Houston is home to several of the major U.S. refineries.

Analysts said as refineries were forced to shut operation in severe weather, gasoline prices rose sharply.

The West Texas Intermediate for October Delivery lost 2.7 percent at 46.57 U.S. dollars a barrel on the New York Mercantile Exchange, while spot prices for U.S. gasoline futures surged 7 percent to a peak of nearly 1.78 per gallon.

Meanwhile, Wall Street was also digesting remarks made at the annual Economic Policy Symposium in Jackson Hole on Friday.

Federal Reserve Chair Janet Yellen said the financial system is safer now than it was during the 2008 financial crisis, though some adjustments may be needed to regulations.

However, Yellen offered no clues about the future of the country's monetary policy.

Expectations for tighter monetary policy in the United States have been dampened recently by soft inflation data. Market expectations for a rate hike in December are just 37.3 percent, according to the CME Group's FedWatch tool.

Investors also kept an eye on the prospects of the U.S. tax reform. President Donald Trump will start campaigning for long-waited tax reform this week, according to his chief economic advisor Gary Cohn.