MOST NOTEWORTHY: Tesoro, Yingli Green Energy and Ensco were today's noteworthy upgrades:

• Deutsche Bank upgraded shares of Tesoro (NYSE: TSO) to Hold from Sell as they believe bankruptcy is not a "major danger" after meeting with management and that recent raise in indebtedness was due to rising working capital requirements combined with negative gasoline cracks.
  
• Citigroup raised Yingli Green Energy (NYSE: YGE) to Buy from Hold following the recent weakness to reflect the company's margin improvement and better visibility into 2009.
  
• Calyon upgraded shares of Ensco (NYSE: ESV) to Add from Neutral as they believe the company's increasing exposure to the deepwater market will drive earnings growth. The firm raised their target to $85 from $74.

OTHER UPGRADES:

• Petrohawk Energy (NYSE: HK) was upgraded at Lehman to Overweight from Equal Weight.
  
• Keefe Bruyette raised Sovereign Bancorp (NYSE: SOV) to Outperform from Market Perform.
  
• Tractor Supply Co (NASDAQ: TSCO) was raised to Buy from Neutral at UBS.

Welcome to the 26th installment of The Wal-Mart Weekly, a column dedicated to bringing you insight, wit, facts, results, opinions and just a bit of everything else when it comes down to a very hot topic these days: Wal-Mart. Last week we wondered whether Always Low Prices was just a myth in today's competitive climate.

This past week, I discussed Wal-Mart (NYSE: WMT) Stores, Inc.'s entry into the non-protected digital music file download business. With the retailer selling non-protected songs from its website for a maximum of $0.94, will this action dent into Apple (NASDAQ: AAPL)'s iTunes market share? Who knows at this point.

Wal-Mart has been in the news quite a bit this past week in regards to a European competitor entering a market Wal-Mart is already in (just not in a big way) -- California. Tesco (LSE: TSCO) said it will be opening smaller-concept stores soon that feature the opposite of the big-box retail feeling of the standard 100,000-square-foot Wal-Mart Supercenter. Tesco's stores will average about 10,000 square feet. What will Wal-Mart do in response?

Stock futures are pointing to a mix to lower open of the U.S. stock markets at this time with the S&P 500 futures showing a possible higher start and the Nasdaq a lower start. Investors await data on the housing market today as they look for direction.

Yesterday, stocks edged lower ending a three-day rally as some housing data released yesterday was weak and oil prices again became a concern and futures closing above $69 a barrel, a nine-month high.

Today, oil prices edged lower, but unrest in Nigeria continued to pressure the market.
What investors are really waiting for today is data on the housing market as May housing starts and building permits are due at 8:30 a.m. EDT. Economists estimate that housing starts fell to an annual rate of 1.48 million in May from 1.53 million in April. Permits are expected to rise to an annual pace of 1.47 million from 1.46 million last month. While housing starts is indeed expected to slip, the forward looking indicator, the permits, is expected to rebound from the 10-year low it reached in April. Try as Wall Street might to get past the weakness in the sector, any indication of worsening or spreading to other sectors will undoubtedly affect the market.

Overseas, Japanese stocks ended flat today as declines in banks and electric utilities offset gains in shipbuilders and paper makers. In general, however, Asian stocks ended higher with Honk Kong Hang Seng index jumping 1.7%. Singapore and South Korea hit new highs.
Meanwhile, European markets are mixed. Some oil stocks showed gains, but retailers, being the worst performers, offset these gains. British supermarket giant Tesco (LSE: TSCO) reported slowing non-food sales and its shares were hit with a 3.2% decline.

Corporate news:

If for some strange reason you missed it yesterday, the chatter that was picked up all day long yesterday ended up being true and Yahoo! Inc. (NASDAQ: YHOO) CEO Terry Semel resigned. He will remain as chairman. Co-founder of Yahoo!, Jerry Yang, was appointed CEO and Sue Decker, president. Here is what Jerry had to say in Yahoo!'s blog, Yodel Anecdotal, about his new job. Here at BloggingStocks we had a myriad of opinions, of course. You can read them on the Yahoo! blog. Yahoo! could give support to the market today, but the question is how much. YHOO is now up 2.6% in pre-market trading (7:28 a.m.). Yahoo rose 3.5% in Germany.

Best Buy Co. Inc. (NYSE: BBY) is set to release its second quarter earnings this morning and at 10:00 a.m. Brian White will be liveblogging the webcast. Here is Brian's earning preview.

Specialty retailers, of course, should employ folks who understand the products they sell. There is a Brentwood, Tennessee outfit that staffs each of its stores with a horse owner, a farmer and a welder. Wonder what they offer? Read on.

Tractor Supply Company (NASDAQ: TSCO) is a retail supplier of products for recreational farmers and ranchers. Offerings include tractor parts, fencing, animal feeds and medicines, tools, truck and trailer parts, garden products, riding mowers, and work clothes. The firm operates 698 stores in the U.S. and Canada. Outlets are generally located in rural areas and the outlying suburbs of cities. Major competitors are Home Depot (NYSE:HD) and Sears Holdings (NASDAQ:SHLD).

The company surprised the Street earlier in the week, when it guided Q1 EPS to 10-12 cents and Q1 revenues to $559.8 million. On average, analysts had been expecting break-even earnings and sales of $526.65 million. Management also said it expected FY07 EPS of $2.49-2.56 ($2.50 consensus) and FY07 revenues of $2.7-2.75 billion ($2.72B consensus).

MOST NOTEWORTHY: WebEx Communications, Inc (WEBX), Avaya Inc (AV), Tractor Supply Co (TSCO), Nokia (NOK) and Mattel, Inc (MAT) were some of today's noteworthy downgrades:

• Wachovia downgraded shares of WebEx Communications Inc (NASDAQ: WEBX) to Market Perform from Outperform to reflect the company's pending acquisition by Cisco Systems (CSCO).
• Bank of America cut Avaya Inc (NYSE: AV) to Neutral from Buy with a $13 target after taking in account the company's acquisition of Ubiquity Software Corp Plc. The firm believes sales may miss consensus for the next few quarters, while gross operating margins could disappoint.
• CIBC downgraded Tractor Supply Co (NASDAQ: TSCO) to Sector Performer from Sector Outperformer. The firm sees some moderate upside for shares of TSCO but says it will be incrementally more difficult to achieve without a major fundamental driver in the near-term.
• WestLB AG downgraded shares of Nokia (NYSE: NOK) to Reduce from Hold.
• Mattel Inc (NYSE: MAT) was cut to Market Perform from Outperform at BMO Capital on valuation.

OTHER DOWNGRADES:

• First Albany downgraded Cerner Corp (NASDAQ: CERN) to Neutral from Buy.
• Keefe Bruyette downgraded A.G. Edwards, Inc (NYSE: AGE) to Market Perform from Outperform on valuation.
• Rodman & Renshaw downgraded shares of Genentech, Inc (NYSE: DNA) to Market Perform from Outperform citing a slowdown in near-term growth and valuation that reflects most of its future growth.
• BMO Capital cut both Anadarko Petroleum Corp (NYSE: APC) and Cabot Oil & Gas Corp (NYSE: COG) to Underperform from Market Perform.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).

MOST NOTEWORTHY: MedImmune, Inc (MEDI), Take-Two Interactive Software (TTWO) and Tractor Supply Co (TSCO) were some of today's more notable downgrades:

• Bear Stearns downgraded MedImmune Inc (NASDAQ: MEDI) to Peer Perform from Outperform based on limited upside over the next 6-12 months.

• Take-Two Interactive Software (Nasdaq: TTWO) was cut by Kaufman to Sell from Hold with a $17 target. Kaufman believes Take-Two is overvalued based on fundamentals.

• Tractor Supply (NASDAQ: TSCO) was downgraded by Matrix to Sell from Hold. The firm expects high livestock feed and fertilizer prices to cut demand for Tractor Supply's target customer base.

OTHER DOWNGRADES:

• Martin Midstream Partners LP (NASDAQ: MMLP) was downgraded to Sector Perform from Outperform based on valuation.

• Friedman Billings cut Opteum Inc (NYSE: OPX) to Underperform from Market Perform citing the mounting losses in sub-prime mortgage loans and notes that servicing rights are also under pressure.

• JP Morgan downgraded OMI Corp (NYSE: OMM) to Neutral from Overweight.

• Kaufman downgraded First Charter Corp (NASDAQ: FCTR) to Market Perform from Outperform, citing the macro environment for the downgrade.

• CIBC downgraded Saifun Semiconductors Ltd (NASDAQ: SFUN) to Sector Performer from Outperform after checks in Asia indicated that Hynix is no longer considering NROM as they believe SFUN's licensing momentum is diminishing.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).