NEW YORK CITY

Two senior congressional Republicans on Tuesday said they were troubled by reports of computer hacking attacks on trading systems run by Nasdaq OMX Group and asked for some answers.

The Dow closed its seventh straight day of gains on Tuesday after McDonald's surprisingly strong sales drove confidence in the economic recovery.

The companies whose shares are moving in early session on Tuesday are: Boyd Gaming, Synchronoss Technologies, Select Medical Holdings, athenahealth, Centene, Avon Products, Steris Corp., Halliburton and Blackbaud.

The companies whose shares are moving in pre-market trade on Tuesday are: Sandisk, ProLogis, Urban Outfitters, Newmont Mining, Ford Motor, Avon Products, Akamai Technologies, Genworth Financial, Nyse Euronext and Sara Lee.

Merger activity drove the Dow and S&P to two-and-a-half-year highs on Monday in the latest in a series of mileposts that point to more gains ahead.

Stocks closed higher on Monday, with merger activity driving the Dow and S&P to fresh two-and-a-half-year highs, the latest in a series of mileposts that point to more gains ahead.

The companies whose shares are moving in pre-market trade on Monday are: Bristol Myers Squibb, Chesapeake Energy, Sprint Nextel, Valero Energy, Bank of America, Aetna, Verizon Communications, Weyerhaeuser, Nvidia and Corning.

Exchange operator Nasdaq OMX Group Inc found suspicious files on its U.S. computer servers and determined one of its Internet-based client applications was potentially affected by hackers, the Nasdaq Stock Market's parent company said on Saturday.

Computer hackers repeatedly entered the network of the company that runs the Nasdaq stock market in the past year, but the trading platform was not compromised, the Wall Street Journal reported on Friday.

The companies whose shares are moving in pre-market trade on Friday are: JDS Uniphase, Aetna, PulteGroup, Symantec, Tesoro, Las Vegas Sands, Fiserv and Wynn Resorts.

The top after-market NYSE gainers on Thursday are: Alliant Techsystems, Goodyear Tire & Rubber, Tyson Foods, Vonage Holdings and China Yuchai International. The top after-market NYSE losers on Thursday are: DHT Holdings, Teekay Tankers, RealD, Las Vegas Sands and Netsuite.

Viacom's quarterly revenue dropped a wider-than-expected 5 percent on the decline of DVD sales at Paramount Pictures and shares fell 3 percent in premarket trading.

The companies whose shares are moving in pre-market trade on Thursday are: Dow Chemical, GameStop, Yum Brands, CF Industries Holdings, Micron Technology, Merck & Co and Cvs Caremark.

Stocks finished narrowly mixed in uneasy trading as the political crisis in Egypt seems to be worsening as fighting between forces supporting President Hosni Mubarak and those who oppose him intensify.

The companies whose shares are moving in pre-market trade on Wednesday are: Electronic Arts, Anadarko Petroleum, Freeport-McMoRan, CME Group, Broadcom, Whirlpool, Boston Scientific and Netflix.

The top after-market NYSE gainers on Tuesday are: First Marblehead, Hershey Foods, MEMC Electronic, Timberland, Elan Corp, United Microelectronics, Bank of Ireland, NRG Energy and RSC Holdings

British carpet and floor covering retailer Carpetright Plc said it expects full-year profits to be below last year and below market expectations, citing lower third quarter sales due to adverse weather conditions and fragile consumer confidence.

The Dow and S&P 500 closed at their highest levels since June 2008 on Tuesday and looked poised for more gains after strong earnings and signs of a surge in U.S. manufacturing.

The companies whose shares are moving in pre-market trade on Tuesday are: Lexmark International, Archer Daniels Midland, Novellus Systems, Advanced Micro Devices, Monster Worldwide, Eastman Chemical, BP and Ventas.

The top after-market NYSE gainers on Monday are: Longtop Financial Technologies, Manitowoc Co, Camelot Information, Concord Medical Services and Aercap Holdings. The top after-market NYSE losers on Monday are: Exterran Holdings, Hovnanian Enterprises, Fifth Street Finance, Seaspan and Nabors Industries.

Despite Verizon's announced intention to acquire Terremark for $1.4 billion, are down virtually across across the board amid violent uprisings in Middle East.