(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 jumped on Monday, with the S&P 500 climbing above key resistance to a record high, as optimism over merger activity helped Wall Street erase this year's early weakness. The Dow Jones industrial average was up 0.79 percent at 16,230.17, the S&P 500 was up 0.77 percent at 1,850.42 and the Nasdaq Composite was up 0.83 percent at 4,298.715.
** CELLADON CORP, $9.67, +27.74 pct
The biotechnology company said it granted to French company Servier an exclusive option to develop its experimental small molecule program to treat diabetes and metabolic disorders, outside the United States. If Servier exercised its option, depending on the outcome of studies, Celladon would receive upfront and milestone payments, as well as royalties on sales. The drugs are being tested in preclinical studies.
At least three brokerages, including Barclays, Wedbush and Stifel started coverage on Celladon with high ratings.
** TRIQUINT SEMICONDUCTOR INC, $11.64, +26.11 pct
** RF MICRO DEVICES INC, $7, +20.48 pct
Radio frequency chipmaker RF Micro Devices will buy peer TriQuint Semiconductor for about $1.6 billion to capture a larger share of the market for chips supplied to Apple Inc and Samsung Electronics Co Ltd.
** TREX CO INC, $82.24, +20.23 pct
The maker of wood and plastic composite products reported a 38 percent jump in fourth-quarter revenue due to higher demand in a recovering U.S. housing market.
** MEN'S WEARHOUSE INC, $48.64, +7.83 pct
** JOS. A. BANK CLOTHIERS INC, $59.94, +8.88 pct
Men's Wearhouse pressed on with its bid for Jos. A. Bank Clothiers, boosting its offer by more than 10 percent in spite of the smaller company's effort to stay independent by buying outdoor clothing retailer Eddie Bauer.
Men's Wearhouse raised its cash tender offer to Jos. A. Bank shareholders to $63.50 per share, from $57.50, and added it could increase the offer to $65 if it was able to conduct limited due diligence.
** FACEBOOK, $70.9499, +3.44 pct
WhatsApp, the world's biggest mobile messaging service, is to add a voice call service for its 450 million customers, laying down a new challenge to telecom network operators just days after it was bought by Facebook for $19 billion.
Facebook would take a pause from major acquisitions after the WhatsApp deal, founder Mark Zuckerberg said in answer to an audience member at Mobile World Congress in Barcelona on whether the social network company would bid for Snapchat, another popular free messaging service.
** BLACKBERRY LTD, $9.84, +7.66 pct
The handset maker said it would make its messaging service, BBM, available to Microsoft's Windows Phone and the upcoming Nokia X platforms in the coming months.
** EBAY INC, $56.445, +3.40 pct
Billionaire investor Carl Icahn accused eBay Chief Executive John Donahoe of failing to spot - or ignoring - conflicts of interest on the company's board and called again for the spinoff of its fast-growing PayPal division. Icahn, who also disclosed a 2.15 percent stake in the e-commerce giant on Monday, said in a letter to shareholders that two long-time board members, Marc Andreessen and Scott Cook, had business interests that directly competed with eBay.
** MAGNUM HUNTER RESOURCES CORP, $8.49, -4.93 pct
The oil and gas producer said fourth-quarter results were hurt by a production downtime at its Mibley gas processing plant in West Virginia and a cut in production at the Ormet Pad at Ohio.
Analysts at Baird Equity Research said Magnum's quarterly production, of 11.3 thousand barrels of oil equivalent per day, came in below their estimates.
** COGENT COMMUNICATIONS GROUP INC , $37.57, -6.61 pct
Netflix on Sunday agreed to pay broadband provider Comcast Corp for faster Internet speeds and deliver its movies and TV programs to Comcast's broadband network directly, cutting out third-party providers such as Cogent.
FBR Capital Markets downgraded Cogent's stock to "underperform" from "market perform" on Monday, saying it expects Verizon and other broadband providers to follow Comcast's lead in giving content companies an incentive to directly deal with them.
The stock had fallen 21.5 percent early in the session.
** GT ADVANCED TECHNOLOGIES INC, $14.105, +16.47 pct
The solar and LED equipment maker said it could turn profitable in the second half of this year, after reporting a smaller-than-expected loss for the fourth quarter ended Dec. 31. The company, which will open a manufacturing facility in Arizona to make sapphire materials for Apple Inc's electronics devices, said about 80 percent of its revenue in 2014 will come from the sapphire business, which makes materials used to manufacture LED chips.
** SPRINGLEAF HOLDINGS INC, $28.18, +7.80 pct
Fortress Investment Group LLC, majority owner of consumer finance company Springleaf Holdings, and some other private equity firms have approached Citigroup Inc about a potential deal for its consumer finance business, OneMain Financial, Reuters said on Friday quoting sources.
The logic of combining Springleaf, whose shares rose about 7 percent on Friday, with OneMain has been apparent to top financiers for years, according to one of the sources.
** SOUFUN HOLDINGS, $75.04, -6.19 pct
Shareholder General Atlantic Mauritius Ltd said late on Friday that it had proposed to sell about 2.53 million shares of Soufun, which operates China's largest real estate internet portal.
** STANDARD MOTOR PRODUCTS INC, $36.45, +13.34 pct
The maker of replacement parts for motor vehicles reported fourth-quarter results that beat analysts' average estimate as sales in its engine management business rose 6.9 percent. The company also announced stock buyback of up to an additional $10 million.
** HUMANA INC, $113.57, +10.46 pct
** UNITEDHEALTH GROUP INC, $76.025, +3.00 pct
** AETNA INC, $71.91, +2.10 pct
** TENET HEALTHCARE CORP, $48.43, +3.33 pct
** WELLCARE HEALTH PLANS INC, $61.81, +1.24 pct
U.S. health insurers including Humana said on Monday that the government's proposed cuts to privately run Medicare programs appear to represent a funding decline of around 4 percent, less than the possible cuts of 7 percent or deeper that analysts had been expecting.
** KANDI TECHNOLOGIES GROUP INC, $15.6624, +17.23 pct
The China-based electric vehicle maker told Bloomberg in an interview that it was looking at expanding its car rental service to Beijing and Shanghai. (r.reuters.com/hyd27v)
** SYNTA PHARMACEUTICALS CORP, $7.03, +9.16 pct
The company said two of its cancer compounds demonstrated anti-tumour activity in multiple animal trials.
** PALO ALTO NETWORKS INC, $76.82, +4.35 pct
The security software maker reported second-quarter revenue that beat Wall Street expectations as subscriptions rose. FBN Securities raised its price target on the stock to $90 from $65.
** OCULUS INNOVATIVE SCIENCES INC, $3.51, -11.59 pct
The company said it entered into agreements with two institutional investors for the sale of 450,620 units at a discount to its share closing price on Friday. Oculus said it expected to raise gross proceeds of $1.35 million from the offering.
** ARMSTRONG WORLD INDUSTRIES INC, $53.67, -9.45 pct
The company, which makes floors and ceilings, reported a fourth-quarter profit well below analysts' estimates as costs rose 10.5 percent.
** CANADIAN SOLAR INC, $39.78, +5.32 pct
The solar company said it would supply 18 megawatts of panels to Japanese electronics maker Hitachi Ltd for a power project. In a separate deal, Canadian Solar said it would supply panels to privately held Strata Solar to power five power projects in North Carolina totaling 30 megawatts
Analysts at JP Morgan Securities began their coverage of Canadian Solar's stock with an "overweight" rating and a price target of $50, citing the company's project pipeline for this year, which could push margins high. Canadian Solar's profit is likely to rise four-fold to $4.31 per share this year on an 87 percent rise in revenue, the analysts wrote in a note to clients.
** ENDOCYTE INC, $15.695, +5.05 pct
The biopharmaceutical company posted a smaller-than-expected quarterly loss, helped by a 19 percent rise in revenue from its partnership with Merck & Co Inc to develop its cancer drug, vintafolide.
** SINA CORP, $76.38, +4.70 pct
The online media firm has hired Credit Suisse AG and Goldman Sachs for a U.S. initial public offering worth about $500 million of its Sina Weibo microblogging service, a source familiar with the plans said on Monday.
** AGENUS INC, $4.23, +9.02 pct
HC Wainwright & Co initiated coverage on Agenus with a "buy" rating, saying the biotechnology company could be a potential buyout target after the acquisition of 4-Antibody AG, a private European-based biopharmaceutical company. The acquisition of Antibody AG adds 6 drug development programs to Agenus' pipeline. The brokerage set a price target of $8 on the stock.
** CELSION CORP, $3.7698, +4.14 pct
The cancer therapy developer said the U.S. Food and Drug Administration has cleared a planned late-stage pivotal trial of its experimental liver cancer treatment, ThermoDox.
Griffin Securities Inc analyst Keith Markey said a second trial is merited as significant improvement was now observed in the subpopulation of the study that failed last year.
Data from the updated study analysis, released last month, indicated that ThermoDox may significantly improve overall survival. Last year, the drug had failed to meet the main goal in a late stage trial.
** PFIZER INC, $32, +1.72 pct
The drug maker said Prevnar 13, its blockbuster vaccine against childhood infections, prevented pneumonia outside of hospitals in people age 65 and older, in one of the largest drug trials ever conducted.
** SCORPIO TANKERS INC, $10.14, +7.64 pct
** FRONTLINE LTD, $4.16, +6.12 pct
Scorpio Tankers reported a quarterly loss, compared with analysts expectations of a profit, but said it expected to turn profitable in the first quarter and raised its quarterly dividend to 8 cents per share from 7 cents. It also said it would buy seven very large crude carriers for about $662.2 million.
Shares of rival Frontline also rose after Scorpio Tankers said vessel rates had improved in the first quarter.
** AU OPTRONICS CORP, $3.32, +4.40 pct
Innolux Corp, the world's No.3 flat-panel maker, declined to rule out a potential merger with smaller rival AU Optronics, but a fund manager said such a potential merger may not be realized soon. (Compiled by Shailaja Sharma in Bangalore; Editing by Don Sebastian)