Analyst upgrades:

• Citigroup upgraded Cooper Industries (NYSE: CBE) to Buy from Hold on valuation as it believes commercial construction concerns are well known. The firm raised its target on shares to $40 from $37, and coupled the upgrade with a downgrade of Rockwell Automation (NYSE: ROK) to Sell from Hold.
• Credit Suisse upgraded BJ Services (NYSE: BJS) to Neutral from Underperform following its acquisition by Baker Hughes (NYSE: BHI). The firm raised its target to $17.
• Credit Suisse also upgraded Amkor Technology (NASDAQ: AMKR) to Outperform from Neutral and raised its target to $8 from $7. The firm expects Amkor to benefit from near-term strength in the supply chain and the mix shift towards higher value packaging.
• Textron (NYSE: TXT) was upgraded to Conviction Buy from Neutral at Goldman.
• Siemens (NYSE: SI) was upgraded to Neutral from Sell at UBS.
• Stanley Works (NYSE: SWK) was upgraded to Buy from Neutral at Janney Montgomery.

• Oppenheimer assumed coverage of Sohu (NASDAQ:SOHU) and upgraded shares to Outperform from Perform as they believe the company is better positioned in an uncertain economy. The firm thinks strength in online games could lead to EPS upside and raised their target to $61 from $53.
  
• Allegiant (NASDAQ:ALGT) was upgraded to Buy from hold at Jesup & Lamont on valuation following the recent weakness.
  
• Suntrust upgraded Prosperity Bancshares (NASDAQ:PRSP) to Buy from Neutral based on valuation. The firm maintains a $30 target on shares.
• LaBranche (NYSE:LAB) was upgraded to Buy from Sell at Goldman.
  
• AU Optronics (NYSE:AUO) was raised to Overweight from Neutral at HSBC.
• Core Laboratories (NYSE:CLB) was upgraded to Overweight from Neutral at JP Morgan.

• Jefferies downgraded shares of BPZ Resources (AMEX:BPZ) to Underperform from Hold as they believe the decline in oil prices and the uncertain credit markets has placed considerable pressure on the company's operations in northwest Peru. The firm maintains a $5 target on the stock.
  
• UBS downgraded StatoilHydro (NYSE:STO) and Repsol SA (NYSE:REP) to Neutral from Buy as they expect 2009 to be a difficult year for European oil and gas companies.
  
• Bernstein downgraded Heinz (NYSE:HNZ) to Market Perform from Outperform and lowered their target to $42 from $62 citing foreign exchange impact and commodity pressures.
• Blackstone Group (NYSE:BX) was downgraded to Underweight from Overweight at Barclays.
  
• Siemens (NYSE:SI) was lowered to Neutral from Buy at Banc of America/Merrill.
  
• Pride International (NYSE:PDE) was cut to Underweight from Neutral at JP Morgan.

• Kaufman Bros. believes GT Solar's (NASDAQ:SOLR) equipment orders are at a bottom and that shares are undervalued. Shares were initiated with a Buy rating and $7 target.
  
• Jefferies assumed L-1 Identity (NYSE:ID) with a Buy rating and $11 target. The firm believes concerns over the company's sensitivity to government budget priorities and elevated levels of debt are overdone.
  
• JP Morgan (NYSE:JPM) was started at Keefe Bruyette with a Market Perform rating and $30 target. Keefe Bruyette sees limited catalysts for the stock as they expect credit headwinds and subdued investment banking revenues to persist over the near-term.
• Legg Mason (NYSE:LM) and T. Rowe Price (NASDAQ:TROW) were initiated with an Equal Weight rating at Barclays.
  
• Electronic Arts (NASDAQ:ERTS) was initiated at Janney Mongtomery with a Neutral rating.
  
• Friedman Billings reinitiated U.S. Bancorp (NYSE:USB) with an Underperform rating and $17 target.

Investors frequently like to chase "hot stocks." While not based on fundamentals, momentum investing does sometimes work as stocks that are "working today" frequently "work tomorrow" as well.

So, as 2008 is 1/6th done, it's time to look back at the highfliers from 2007 and see where they're trading today. As usual, the analysts at Bespoke Investment Group have some good data and charts for us.

In a post, titled "How the Best Have Done," Bespoke analyzes the best performing U.S. stocks of 2007 and tracks them into 2008. The results:

• First Solar Inc. (NASDAQ: FSLR), 2007's best performer, is down 21.86% year to date. See BloggingStock's Aaron Katsman's article on why he shorted this stock into the New Year.
  
• The second best, Onyx Pharma Inc. (NASDAQ: ONXX), is down 49.51%.

While some solar stocks are down big in 2008 after a huge run-up in 2007, the big winners are heavily concentrated in materials, agriculture, and energy. BPZ Resources Inc. (AMEX: BZP) is the stock on the list that has done the best in 2008 -- rising another 44% so far this year.

Zack Miller is the managing editor of IsraelNewsletter.com and a former equity analyst for a leading multinational hedge fund.