Twitter
Shares of Twitter Inc. (NYSE: TWTR) fell 3.93 percent to close at $66.29 on Monday after Morgan Stanley cut its rating on the company and said investors should sell the shares because the microblogging service may lose online advertising revenue to larger rivals, such as Facebook Inc. (NASDAQ: FB). Reuters

Wall Street closed lower Monday, with the S&P 500 declining for a third straight session, as mixed data weighed on investors ahead of Wednesday’s release of the Federal Open Market Committee’s latest minutes from its policy meeting last month, along with the highly anticipated December employment report on Friday.

The Dow Jones Industrial Average lost 44.89 points, or 0.27 percent, to close at 16,425.10. The S&P 500 Index fell 4.60 points, or 0.25 percent, to end at 1,826.77. The Nasdaq Composite fell 18.23 points, or 0.44 percent, to 4,113.68.

In corporate news, Standpoint Research downgraded Apple Inc. (NASDAQ:AAPL) and Amazon.com, Inc. (NASDAQ:AMZN) on Monday, citing "moral reasons," CNBC reported. The iPhone maker’s stock was downgraded from "hold" to "sell," while the firm reiterated a "sell" recommendation for shares of Internet retail giant Amazon.

“For Apple Computers to pay their workers $2 an hour while they have $150 billion in the bank is nothing short of obscene. They have workers who are doing back-breaking and eye-burning work in depressed states of mind and in many instances have already committed suicide,” said Ronnie Moas, Standpoint Research's founder and director of research. “Instead of treating their employees like human beings, they are treated like animals. If it were not for their employees, Apple would not be where it is today. But instead of giving these people a better life, they give these people the bare minimum and defend this action with the argument that the wage is higher than the average there and in line with what their competitors are paying.”

Tech giant Apple closed Monday’s session up 0.55 percent to $543.93 a share, while Amazon stock edged down 0.71 percent to close at $393.63.

Shares of Twitter Inc. (NYSE:TWTR) fell 3.93 percent to close at $66.29 on Monday after Morgan Stanley cut its rating on the company and said investors should sell shares because the microblogging service may lose online advertising revenue to larger rivals, such as Facebook Inc. (NASDAQ:FB). Shares of social media company Facebook rose 4.84 percent to close at $57.20.

After the closing bell, Federal Reserve Vice Chair Janet Yellen was confirmed by the U.S. Senate as head of the Federal Reserve. Yellen, 67, will succeed current Fed Chairman Ben Bernanke, whose second term ends Jan. 31.The confirmation follows the Fed’s surprise announcement in December the central bank will scale back its $85 billion-a-month bond-buying program to $75 billion this month.

Ahead on this week’s economic calendar, the FOMC will release minutes from its last policy meeting on Wednesday and the U.S. Labor Department is scheduled to release its employment report for December.

In other news, Sonic Corporation (NASDAQ:SONC) reported fiscal first-quarter earnings of 13 cents a share on revenue of $126.7 million, compared with Wall Street expectations of earnings per share of 13 cents on revenue of $128 million. Shares of the restaurant chain jumped 3.64 percent to $19.95 in after-hours trading.

Notable companies reporting earnings this week include Micron Technology Inc. (NASDAQ:MU) and Apollo Education Group Inc. (NASDAQ:APOL) on Tuesday, Monsanto Company (NYSE:MON), Family Dollar Stores Inc. (NYSE:FDO) and Bed Bath & Beyond Inc. (NASDAQ:BBBY) on Wednesday, followed by Alcoa Inc. (NYSE:AA) on Thursday.