(For more market insights, including options activity, click on ; for the Day Ahead newsletter link.reuters.com/mex49s; for the Morning News Call newsletter, link.reuters.com/nex49s) U.S. stocks opened flat in what is expected to be holiday-thinned trading on Monday, on the heels of the best two-week advance for the S&P 500 in five months and ahead of data on the housing market. The Dow Jones industrial average was up 0.02 percent at 16,481.97, the S&P 500 was down 0.09 percent at 1,839.69 and the Nasdaq Composite was down 0.16 percent at 4,150.002.
** TWITTER INC, $52.93, +0.25 pct
The microblogging site's shares continued to slide for the second day. Macquarie Equities Research downgraded the stock on Friday, citing lack of fundamental backing to the high valuation of its stock.
Twitter shares fell about 13 percent on Friday. It has risen nearly 150 percent from its IPO price of $26.
In an article on Sunday, a New York Times report also questioned the company's high valuation. (link.reuters.com/myb75v)
** CROCS INC, $15.62, +17.18 pct
The shoemaker said Blackstone Group LP is making a $200 million investment that will give the private equity firm a 13 percent stake in the shoe company.
In exchange for the $200 million, Blackstone will receive preferred stock that can convert to common stock in three years if certain conditions are met. It will also receive two board seats.
Crocs also said Chief Executive John McCarvel plans to retire in April and will also give up his seat on the company's board.
Sterne Agee & Leach upgraded its rating on the stock to "neutral" from "underperform," saying the retirement of the CEO McCarvel "removes a large road block to success."
The brokerage also said Blackstone's involvement may serve as a catalyst for positive change, including closing underperforming stores and limiting future store openings.
** WPCS INTERNATIONAL INC, $2.05, -18.97 pct
The company, which also operates a Bitcoin trading platform BTX Trader, received a notice of resignation from its independent registered public accounting firm on Dec. 20, according to the website thestreetinsider.com. The resignation of the former accountant was not recommended or approved by the audit committee or board of directors of the company, the website reported.
** NOAH HOLDINGS LTD, $17.23, -11.28 pct
The wealth management service provider appointed Zhiwu Chen as an independent director to its board, effective from December 13, 2013. Chen will also join the company's corporate governance and nominating committee, replacing Ji Liu, who resigned from the board of directors of the company, effective Dec. 13, 2013.
** MECHEL OAO, $2.6, +6.12 pct
The board of the loss-making Russian coal miner and steelmaker will discuss the early resignation of CEO Evgeny Mikhel at a meeting on Monday, Mechel said in a regulatory statement.
** INVENSENSE INC >, $19.6, +8.65 pct
Brokerage Northland Capital reiterated its "outperform" rating on the chipmaker's stock, as it expects catalysts such as wider use of image stabilization in smartphones and wearable computers to fuel demand for the company's motion sensors and gyroscopes in 2014.
** NQ MOBILE, $14.02, +18.31 pct
Shares of the Chinese mobile security software maker jumped after Morgan Stanley reported a 5.2 percent passive stake as of Dec. 20 in a regulatory filing.
** CRACKER BARREL OLD COUNTRY STORE INC, $110.17, -0.98 pct
The restaurant chain said its board has considered top shareholder Sardar Biglari's letter demanding the company begin a sale process and concluded that the continued execution of its existing business strategy is the proper course of action for the company's long-term best interests.
** SCORPIO TANKERS INC, $11.71, -0.85 pct
The tanker company said it would earn about $14 million from previously announced sale of very large gas carrier and from write down of some of the older vessels in the fleet that the company has designated for sale.
** REAL GOODS SOLAR INC, $3.031, +7.86 pct
The solar system installer said its commercial and utility division, RGS Energy, would co-develop seven solar projects totaling 4.5 megawatts (MW) in Vermont, along with a privately held company, Green Lantern Capital.
** SANOFI SA, $52.93, +0.25 pct
The French drugmaker's Lemtrada multiple sclerosis treatment has failed to win approval from regulators in the United States, dealing a setback to a drug which was at the heart of Sanofi's $20 billion takeover of U.S. biotech firm Genzyme. The U.S. Food & Drug Administration rejected Lemtrada for launch in the world's biggest drug market on the grounds that Genzyme had not shown its benefits outweighed its "serious adverse effects," the company said on Monday.
** BIOLASE INC, $3.06, +17.69 pct
The dental device maker said Canadian health regulators approved its soft-tissue diode laser for marketing in Canada.
** KANDI TECHNOLOGIES GROUP, $12.18, +17.80 pct
Call buyers stepped into the Chinese electric car maker on Friday, sending up the stock to close 26 percent higher at $10.34. WhatsTrading.com options strategist Frederic Ruffy said the reason for the move was not clear.
** MYRIAD GENETICS INC, $20.7, -14.25 pct
At least three brokerages said a statement from the Centers of Medicare & Medicaid Services confirmed that the reduced reimbursement for its genetic breast cancer tests was not a clerical error, as the company had said in October.
JMP Securities analyst J. T. Haresco cut his rating on the stock and said, "With increasing competitive pressure, additional clarity on pricing, and the lack of near-term growth drivers to offset pricing declines, we see little reason to own shares at current levels."
William Blair analyst Amanda Murphy wrote in a note that the company might have to lower its 2014 forecast to account for the fall in revenue from the tests.
** WELLS FARGO & CO, $45.53, +0.07 pct
The fourth-largest U.S. bank by assets, said it would pay $591 million to Fannie Mae to substantially settle all repurchase liabilities related to loans sold to the government-controlled mortgage company before Jan. 1, 2009.
** COCA-COLA CO, $40.99, +0.81 pct
The beverage maker's shares could see steep upside next year, following an extended period of relative underperformance compared with major indexes, Barron's wrote on Sunday. The financial publication also said Coca-Cola stands to benefit from a growing global middle class, which it estimated could result in a doubling of soft drink sales over the next 10 to 15 years.
** VANGUARD NATURAL RESOURCES LLC, $29.46, +1.72 pct
The company said it entered into a definitive agreement to buy natural gas and oil properties in the Pinedale and Jonah fields of southwestern Wyoming for $581 million from an unnamed source.
** MONDELEZ INTERNATIONAL INC, $35.04, +0.37 pct
The packaged foods company has sold its SnackWell's cookies and snacks business to its joint venture with Brynwood Partners VI LP, the private equity firm said on Monday.
** CUBIST PHARMACEUTICALS INC, $68.15, +1.17 pct
The company said U.S. health regulators granted priority review to its antibiotic tedizolid phosphate for the treatment of a type of bacterial skin infection, and set a review date of June 20, 2014.
This status allows for an expedited review process for medicines that are considered potentially significant therapeutic advancements over existing therapies.
** VITRAN CORP INC, $6.46, -3.44 pct
The Canadian transport company Transforce Inc said one of its affiliates would acquire shares of smaller rival Vitran, not already owned by the company for $6.50 each, a discount of 3 percent to the stock's Friday close.
** BANK OF AMERICA CORP, $15.572, -0.63 pct
A federal judge on Friday approved the bank's $39 million settlement of a gender discrimination lawsuit by female brokers over objections that the accord would enshrine bias on Wall Street.
** COOPER TIRE & RUBBER CO, $23.14, +0.78 pct
The tiremaker said it was not going ahead with a $2.5 billion merger with India's Apollo Tyres Ltd. Cooper said Apollo notified it that financing for the deal was no longer available.
** SONY CORP, $17.36, +1.58 pct
The Japanese electronics company has decided not to sell its lithium-ion battery unit, media reported on Sunday, in a gamble that it can turn the business around with a weak yen and growing demand for smart phone batteries.
** TRINA SOLAR LTD, $14.07, +7.00 pct
The Chinese solar company said on Monday it signed a framework agreement with a local government authority to develop a 1 gigawatt power plant project in western China's Xinjiang region. The plants would be built over four years, starting from early 2014, Trina Solar said.
** RENESOLA LTD, $3.51, +4.46 pct
The Chinese solar panel maker signed a memorandum of intent to sell three power projects with a total capacity of 60 megawatts in western China to Jiangsu Akcome Solar Science & Technology Co Ltd. ReneSola did not disclose financial details of the planned transaction and said it does not mean that a final deal has been reached.
** THRESHOLD PHARMACEUTICALS INC, $4.74, +1.07 pct
The company completed a target enrollment of 620 patients with advanced soft tissue sarcoma in a late-stage trial testing its lead drug, triggering a milestone payment of $12.5 million from Germany-based Merck KGaA. Threshold has a global license and co-development agreement with Merck for the cancer drug, TH-302, which includes an option for Threshold to co-market it in the United States.
** ABBOTT LABORATORIES, $38.34, -0.08 pct
Abbot has agreed to pay the United States $5.48 million to resolve allegations that it paid improper kickbacks to induce doctors to use some of its products, the U.S. Department of Justice said on Friday.