New York, July 29th (TradersHuddle.com) – Following are some of the top upgrades and downgrades before the market open.

Upgrades:

Boeing (NYSE:BA), the aircraft maker and Defense Company, was upgraded to a Hold from Sell at Societe Generale.

Colfax (NYSE:CFX), the maker of pumps and specialty valves, was upgraded to a Buy from Hold at BB&T, with a $16 target price.

Compellent Technologies (NYSE:CML), the supplier of storage area networks, was upgraded to a Hold from Sell at Canaccord Genuity.

Citrix Systems (NASDAQ:CTXS), the only enterprise software company with end-to-end virtualization, was upgraded to a Neutral from Underperform at Cowen. Citrix was also upgraded to a Buy from Hold at Deutsche Bank.

DST Systems (NYSE:DST), the information processing and computer software services, was upgraded to Outperform from Neutral at Robert W. Baird. The firm raised its target price to $50 from $48, as improving trends encourages them.

Equinix (NASDAQ:EQIX), the provider of core Internet exchange services, was upgraded to Outperform from Perform at Oppenheimer. The firm set a target price of  $115 based on improving visibility into 2H10 and 2011 growth trends; faster-than-expected realization of synergy benefits from their recent acquisition, generating margin expansion in 4Q10 and beyond; and increased scale. The firm believes Equinix is in a dominant market position, providing pricing power.

Flagstar Bancorp (NYSE:FBC) was upgraded to Outperform from Market Perform at FBR Capital. The firm maintained its $5 target price following earnings report that showed, higher than estimated credit costs, with improving core-operating trends.

Meritage Homes (NYSE:MTH), the homebuilder, was upgraded to Neutral from Sell at UBS.

Downgrades:

Advanced Micro (NYSE:AMD), the world’s second largest chipmaker, was downgraded to Market Perform from Outperform at FBR Capital. The firm lowered its target price to $11 from $14 given that heightened macroeconomic risks continue to build; PC build plans continue to get reduced; Nvidia and others have pointed to signs of PC cost-reduction efforts that may affect GPU attach rates.

AMAG Pharmaceuticals (NASDAQ:AMAG) was downgraded to a Neutral from Outperform at Robert W. Baird. The firm lowered its target price to $36 from $40 saying while still positively inclined long term, they see commercial hurdles increasing for Feraheme over the next several quarters.

Frontier Oil  (NYSE:FTO) was downgraded to a Neutral from Outperform at Macquarie.

Kirby Corporation (NYSE:KEX), the operator of fleet of inland tank barges, was downgraded to a Hold from Buy at BB&T.

Lan Airlines S.A. (NYSE:LFL), the Chilean based airline, was downgraded to a Neutral from Overweight at JP Morgan.

NRG Energy (NYSE:NRG) was downgraded to a Hold from Buy at Deutsche Bank.

NVIDIA (NASDAQ:NVDA), the world leader in visual computing technologies, was downgraded to Market Perform from Outperform at FBR Capital. The firm lowered its target price to $10 from $18 following lowered guidance. The firm says their late-May upgrade call has not panned out given Apple may expel Nvidia's chipsets from its PCs sooner than expected; Nvidia's transition to more expensive 40nm-based Fermi GPUs when the world is seeing macroeconomic "choppiness" and global PC demand/production rationalization likely impacted GPU attach rates and Nvidia's overall mix.

Sycamore (NASDAQ:SCMR), the provider of software-based optical networking products, was upgraded to Outperform from Neutral at Credit Suisse.

Symantec (NASDAQ:SYMC), the provider of solutions to manage IT risk and maximize IT performance, was downgraded to Market Perform from Outperform at FBR Capital. The firm lowered its target price to $15 from $20 following last night’s earnings report, as the company modestly missed the Street across the board. FBR noted that while the headline was negative, the company did post a respectable performance on the enterprise and consumer security segments, a nice positive in an otherwise gloomy report and outlook. Symantec was also downgraded to Market Perform from Outperform at Morgan Keegan.

TriQuint Semiconductor (NASDAQ:TQNT) was downgraded to Market Perform from Buy at Charter Equity following earnings. The firm says while they expect a reacceleration in growth for both revenue and margins once new capacity is brought on-line, that isn't likely to occur for at least a quarter, perhaps two.

Vistaprint  (NASDAQ:VPRT) was downgraded to Market Perform from Outperform at Barrington Research given given the disappointing earnings results, lower-than-expected fiscal 2011 guidance and execution issues cited by management. Vistaprint was also downgraded to a Hold from Buy at Citigroup.

Stericycle (NASDAQ:SRCL), the medical waste management services provider, was downgraded to a Hold from Buy at Soleil.