Stocks on Wall Street finished little changed on Monday as investors focused on the effects of Tropical Storm Harvey.
Insurance companies and oil drillers stumbled while refineries rose along with petrol prices.
With August coming to a close, Monday was one of the quietest days of the year on Wall Street, although b iotech drug companies rose after hepatitis C and HIV drug maker Gilead Sciences agreed to buy cancer drug maker Kite Pharma for 11.9 billion dollars.
Travel booking website Expedia tumbled as investors expected the company's chief executive, Dara Khosrowshahi, to leave the company to become chief executive of ride-sharing company Uber.
Lacking other major corporate or economic news, investors mostly focused on Harvey, which continues to hit parts of the Gulf Coast with historically heavy rains.
Large parts of the energy and petrochemical industries are based there and companies with a lot of stores in the area stand to lose business. While petrol price spikes will be temporary, other effects of the storm will last for years.
"There will be ripple effects that everyone is going to feel," said Jack Ablin, chief investment officer for BMO Capital Markets.
He said that could include higher insurance premiums, as the storm is likely to cause tens of billions of dollars in flood damage.
Mr Ablin said the storm might affect interest rates as well, as the Federal Reserve might hesitate to raise interest rates if they think the storm will slow the economy significantly.
The Standard & Poor's 500 index picked up 1.19 points, or less than 0.1%, to 2,444.24. The Dow Jones industrial average dipped 5.27 points to 21,808.40.
The Nasdaq composite rose 17.37 points, or 0.3%, to 6,283.02. The Russell 2000 index of smaller-company stocks gained 4.78 points, or 0.3%, to 1,382.23. Most of the stocks on the New York Stock Exchange fell.
The tropical storm, which made landfall in Texas on Friday, is expected to continue for days, and the National Weather Service says some parts of Houston and its suburbs could get as much as 50 inches of rain.
The weather shut down much of Texas' oil and gas industry, and S&P Global analysts said about 2.2 million barrels per day of refining capacity was down or being shut down by Sunday.
Helmerich & Payne, an oil and gas well drilling contractor, gave up 1.29 dollars, or 2.9%, to 43.49 dollars.
Benchmark US crude fell 1.30 dollars, or 2.7%, to 46.57 dollars a barrel in New York. Brent crude, the international standard, lost 52 cents, or 1%, to 51.89 dollars a barrel in London.
The CAC 40 in France fell 0.5% and the DAX in Germany sank 0.4%. British markets were closed for a public holiday.
Japan's benchmark Nikkei 225 index took a negligible loss and the South Korean Kospi lost 0.4%. The Hang Seng in Hong Kong rose less than 0.1%.