Here are some highlights from this past week's earnings coverage from BloggingStocks:

• Amazon.com Inc. (NASDAQ: AMZN) reported strong Q1 results easily beat expectations.
• Bank of America Corp. (NYSE: BAC) posted better-than-expected Q1 earnings, helped by home refinancing.
• Caterpillar Inc. (NYSE: CAT) reported its first quarterly loss since 1992 and cut its revenue outlook.
• Coca-Cola Co. (NYSE: KO) posted Q1 earnings that were in line with expectations, but shares fell.
• eBay Inc. (NASDAQ: EBAY) posted better-than-expected Q1 earnings despite a decline in sales.

MOST NOTEWORTHY: Vodafone, Citrix Systems, STMicroelectronics, Symmetricom and Smith International were today's noteworthy upgrades:

• JP Morgan upgraded shares of Vodafone Group (NYSE: VOD) to Overweight from Neutral, as they believe the company is benefiting from increased data sales.
  
• Citrix Systems (NASDAQ: CTXS) was upgraded to Outperform from Market Perform at Friedman Billings. The firm's checks indicate that its clear communication strategy and a stronger technology platform behind the Enterprise and Platinum editions is spurring top line growth.
  
• Baird upgraded shares of STMicroelectronics (NYSE: STM) to Outperform from Neutral based on new product cycle, multiple design wins, valuation, and strong Q4 guidance.
  
• Cantor upgraded shares of Symmetricom (NASDAQ: SYMM) to Buy from Hold as they find the valuation compelling and are comfortable with Q1 estimates.
  
• Calyon Securities upgraded Smith International (NYSE: SII) to Add from Neutral following its Q3 report and guidance.

OTHER UPGRADES:

• Shaw Group (NYSE: SGR) was upgraded to Neutral from Sell at Goldman Sachs.
  
• RBC Capital upgraded QLogic Corporation (NASDAQ: QLGC) to Outperform from Sector Perform.
  
• Credit Suisse upgraded Amgen (NASDAQ: AMGN) and Weatherford (NYSE: WFT) to Outperform from Neutral.

MOST NOTEWORTHY: Nasdaq Stock Market, Family Dollar, Circuit City, Wells Fargo and Key Corp were today's noteworthy downgrades:

• Credit Suisse downgraded Nasdaq Stock Market Inc (NASDAQ: NDAQ) to Market Perform from Outperform on valuation.
  
• JP Morgan expects Family Dollar Stores Inc (NYSE: FDO) to face macro pressures and increased competition from Wal-Mart Stores Inc (NYSE: WMT) and Dollar General.
  
• Bear downgraded shares of Circuit City Stores Inc (NYSE: CC) to Peer Perform from Outperform based on lack of visibility, execution issues, softer consumer environment, potential pricing disruptions, and product cycle concerns.
  
• Merrill downgraded shares of Wells Fargo and Company (NYSE: WFC) to Neutral from Buy to reflect higher credit losses and valuation and KeyCorp (NYSE: KEY) to Sell from Neutral to reflect the company's "weak" revenue growth.

OTHER DOWNGRADES:

• B. Riley downgraded shares of Iris International Inc (NASDAQ: IRIS) to Neutral from Buy.
  
• Soleil downgraded ExpressJet Holdings Inc (NYSE: XJT) to sell from Hold.
  
• Calyon downgraded Weatherford International (NYSE: WFT), Transocean Inc (NYSE: RIG) and Diamond Offshore Drilling Inc (NYSE: DO) to Add from Buy.

MOST NOTEWORTHY: The U.S. media sector, oil services, MercadoLibre and Horsehead Holdings were today's noteworthy initiations:

• Credit Suisse initiated coverage of the U.S. media sector with a Market Weight rating, shares of The Walt Disney Company (NYSE: DIS) with an Outperform rating and shares of Time Warner Inc (NYSE: TWX) and Viacom Inc (NYSE: VIA.B) with Neutral ratings.
  
• Bernstein initiated coverage of the oil services sector with a Positive Bias rating. The firm initiated Weatherford International Ltd (NYSE: WFT) with an Outperform rating and $84 target and Halliburton Company (NYSE: HAL), Baker Hughes Incorporated (NYSE: BHI) and Schlumberger Limited (NYSE: SLB) with Market Perform ratings and a $44 target, $103 target and $96 target, respectively.
  
• MercadoLibre Inc (NASDAQ: MELI) was initiated by American Technology with a Buy rating and $45 target, as the firm believes the e-commerce growth opportunity in Latin America is still in its infancy. Shares were also started at Pacific Crest with an Outperform rating and $37 target, as the firm believes the company should benefit from strong secular growth and company-specific drivers. MercadoLibre was also initiated at JP Morgan with an Overweight rating and at Merrill Lynch with a Buy rating and $35 target.
  
• Friedman Billings expects Horsehead Holding Corp's (NASDAQ: ZINC) EBITDA to increase even in a declining commodity environment and believes the company is well positioned to gain market share. Shares were started with an Outperform rating and $27 target also added to the firm's Top Pick List.

OTHER INITIATIONS:

• Citigroup started shares of Companhia Vale do Rio Doce (NYSE: RIO) with a Buy rating and shares of StealthGas Inc (NASDAQ: GASS) with a Hold rating and $20 target.
  
• Roth Capital started shares of Internap Network Services Corporation (NASDAQ: INAP) with a Buy rating and $19 target.
  
• Raymond James initiated Atmel Corporation (NASDAQ: ATML) with an Outperform rating and Argo Group Internaional Holdings Ltd (NASDAQ: AGII) with a Strong Buy rating.

This is the week that was, or, actually, wasn't. Lots of talk in lots of industries, but not much action. Here's a sampler...

JEFFERIES GROUP, INC. (NYSE: JEF)

The investment bank may be a takeover target. MassMutual, or Massachusetts Mutual Life Insurance Co., may be the pursuer. Could make sense. Jefferies has lots of clients; MassMutual has big bucks. Back in the good old days of 2004 they actually worked together on a corporate lending venture. The two CEOs are buddies. We don't know if that's means fishin', huntin' or bridge. But buddies talk, don't they? Jefferies' stock is clearly on the rise.

WEATHERFORD INTERNATIONAL LTD (NYSE: WFT)

Now that Halliburton Company (HAL) has finished up in Iran, and is done with KBR, word is that they have oil and gas equipment and services provider Weatherford in their sights. That can't be too hard seeing that they have a lot in common and both operate out of Houston. Weatherford's shares have been trading in the high 40s, up some, higher than the lows and lower than the highs of the last many weeks. Not much has happened in the last few days, but maybe it's because those good 'ol boys are deciding whose barbeque place to meet at.

USG CORP. (NYSE: USG)

This one's been around for a while now, and it's worth noting that it's still around, and may be for a while longer. The stock seems poised for a breakout. Is Berkshire Hathaway's Warren Buffett about to make his move? "Yes, hello. I'm calling with a few questions for Mr. Buffett, please...yes, I'll wait..."