US stocks reversed early gains to close mildly as Wall Street digested a batch of downbeat economic reports.
The Dow Jones Industrial Average fell 31.13 points, or 0.17 percent, to 17,792.68 on Monday, Xinhua reported.
The S&P 500 lost 2.58 points, or 0.12 percent, to 2,086.59. The Nasdaq Composite Index edged down 2.44 points, or 0.05 percent, to 5,102.48.
US total existing-home sales fell 3.4 percent to a seasonally adjusted annual rate of 5.36 million in October, down from 5.55 million in September and missing market consensus, the National Association of Realtors said on Monday.
"Existing home sales softened in October after rising to the second highest level since 2007 in September. The housing market has recovered much of its lost momentum this year, and is likely to finish the year on a solid, albeit unremarkable, note in the coming months," said Sophia Kearney-Lederman, an economic analyst at FTN Financial.
The seasonally adjusted Markit Flash US Manufacturing Purchasing Managers' Index (PMI) came in at 52.6, down from 54.1 in October. The figure pointed to the slowest improvement in overall business conditions since October 2013.
Meanwhile, Wall Street continued to weigh the likelihood of a December rate hike by the US central bank. Expectation for a rate hike in December mounted after the release of the minutes from the Federal Reserve's October meeting.
Market expectations were further buoyed as San Francisco Fed president John Williams said at the weekend that there is a strong case for the Fed to begin raising short-term interest rates.
In corporate news, US drug giant Pfizer Inc. and Ireland-based Allergan PLC on Monday announced a merge deal worth up to approximately $160 billion that would create the world's largest pharmaceutical firm.
The takeover would be the largest tax inversion deal ever, moving one of the top corporate names in the United States to a foreign country, the Wall Street Journal reported.
Shares of the former, however, fell 2.64 percent to $31.33 apiece on Monday after the announcement, while shares of the latter also dropped 3.44 percent to $301.72 apiece.
The CBOE Volatility Index, often referred to as Wall Street's fear gauge, rose 0.97 percent to end at 15.62 on Monday.
