US benchmark equity indexes closed lower Wednesday as traders assessed the latest corporate earnings and economic data.

The Nasdaq Composite fell 1.6% to 18,276.7, while the Dow Jones Industrial Average dropped 1% to 42,515. The S&P 500 lost 0.9% to 5,797.4. Consumer discretionary and technology saw the steepest declines among sectors. Only real estate and utilities closed higher.

In company news, Enphase Energy (ENPH) shares slumped nearly 15%, the worst performer on the S&P 500. The company's Q3 financial results fell short of Wall Street's expectations late Tuesday, prompting rating downgrades by multiple analysts.

CoStar Group (CSGP) shares decreased 5.3%, among the worst performers on the S&P 500 and the Nasdaq. Late Tuesday, the company logged Q3 revenue that missed the Street's views.

McDonald's (MCD) saw the steepest decline on the Dow and among the steepest on the S&P 500 Wednesday, down 5.1%. US health authorities said they are investigating an E. coli outbreak in several states linked to the fast-food giant's Quarter Pounder burgers.

Teledyne Technologies (TDY) was the second-best performer on the S&P 500, up 6%, following a Q3 beat.

AT&T (T) posted an unexpected quarterly decline in revenue amid challenges in business wireline that led to a multi-billion dollar write-down, though it remains on track to meet its full-year targets. The company's shares rose 4.6%, among the top gainers on the S&P 500.

The US 10-year yield increased 3.2 basis points to 4.24%, while the two-year rate added 4.1 basis points to 4.08%.

In economic news, economic activity was "little changed" in almost all Federal Reserve districts since early September, though the long-term outlook reflected slightly better optimism, the central bank said in its latest Beige Book. Manufacturing activity fell in most districts, according to the report, which was prepared based on information collected by Oct. 11.

US existing home sales unexpectedly dropped in September, though signs usually tied to higher sales are emerging, according to data released by the National Association of Realtors.

"There are more inventory choices for consumers, lower mortgage rates than a year ago and continued job additions to the economy," NAR Chief Economist Lawrence Yun said.

Mortgage application volume in the US declined for the fourth consecutive week to its lowest point since July amid lower purchase and refinancing activities, the Mortgage Bankers Association said.

West Texas Intermediate crude oil dropped 1.1% to $70.98 a barrel Wednesday.

Commercial crude stockpiles in the US rose by 5.5 million barrels to 426 million barrels through the week ended Friday, the Energy Information Administration said. The consensus was for a gain of 1 million barrels, according to a Bloomberg poll.

Gold fell 1.1% to $2,730.10 per troy ounce, while silver dropped 3.4% to $33.85 per ounce.