Energy shares dragged Wall Street lower on Monday as crude prices fell further, while readings on the services sector and home sales came in below forecasts.

Brent crude oil LCOc1 fell below $85 a barrel and U.S. crude CLc1 dipped below $80 after Goldman Sachs slashed its price forecasts, citing abundant supply and lackluster demand. The S&P 500 energy sector .SPNY was down 2.6 percent, the largest decline among the top ten industry groups.

The fall in crude "is probably good for consumers but there are a number of energy stocks on the S&P 500 getting hit on concern about their earnings," said Bruce Zaro, chief technical strategist at Bolton Global Asset Management in Boston.

He said, however, the decline is "net positive" as it frees cash from consumers.

The Dow Jones industrial average .DJI fell 25.56 points, or 0.15 percent, to 16,779.85, the S&P 500 .SPXlost 6.47 points, or 0.33 percent, to 1,958.11 and the Nasdaq Composite .IXIC dropped 14.19 points, or 0.32 percent, to 4,469.52.

Shares of Brazilian companies traded in the United States tumbled after incumbent Dilma Rousseff won reelection in a runoff vote, defeating centrist and market favorite Aecio Neves by a slim margin. Petrobras ADRs (PBR.N) slumped 13.8 percent to $11.15 and Vale (VALE.N) lost 5.8 percent to $10.51. Itau Unibanco (ITUB.N) fell 6.2 percent and Banco Bradesco (BBD.N) lost 7.7 percent.

A Brazilian exchange-traded fund (EWZ.P) dropped 6.4 percent to $38.93.

The pace of growth in the U.S. services sector in October was at its slowest in six months and contracts to buy previously owned U.S. homes rebounded less than expected in September.

German business sentiment fell in October for a sixth straight month to its lowest level in almost two years, adding to recent concerns the largest European economy may continue to struggle to grow.

Micron (MU.O) shares rose 2.6 percent to $31.86 after it announced a $1 billion stock buyback authorization.

Sarepta Therapeutics (SRPT.O) shares fell 30 percent to $16.48 after it said the U.S. Food and Drug Administration requested additional data regarding a marketing application for its experimental muscle disorder drug.

A 5-year-old boy who arrived in the United States on Saturday from Guinea is being observed in isolation at Bellevue Hospital in New York City for possible Ebola symptoms, according to media reports on Monday.