Typically, when a company announces a large acquisition, the stock price takes a dip. But sometimes a deal is highly strategic and will result in quick results -- and yes, investors will respond.

This is certainly the case with the James River Coal Company (JRCC). It has agreed to pay $475 million for two coal companies: International Resource Partners and Logan & Kanawha Coal. On the news, the shares of James River soared 15% to $23.31.

With crude oil prices soaring, shares in coal and fertilizer companies have also been climbing for the past year. Barron's offers a survey of the momentum plays, pointing out some opportunities and risks when investing in coal and fertilizer stocks.

Talking about risks, Barron's underlines the fact that it can be difficult for investors to put their hard earned money into a stock that is already trading near its highs. But as they say, the trend is up unless proven otherwise, and we might take this into account when picking our trades. For example, back in April, it looked like Mosaic Co. (NYSE: MOS) was facing technical weakness, but this did not last long and the company was able to rebound.

Now let's take a took at the coal sector. Data shows that the Dow Jones U.S. coal index gas gained more than 50% for the past year. While James River Coal Co. (NASDAQ: JRCC) has quadrupled this year, Peabody Energy Corp. (NYSE: BTU) has been seeing some weakness, and this might be a sign that the sector could face tough times ahead. The first concern tied to supply and demand appeared for Peabody when we began to notice that volume on rally days slipped, while volume on declining days has increased.

MOST NOTEWORTHY: BP, LMI Aerospace and Smith & Nephew were among today's noteworthy upgrades:

• Credit Suisse upgraded BP (NYSE: BP) following the company's strong Q1 report.
  
• Wachovia upgraded LMI Aerospace (NASDAQ: LMIA) based on valuation and potential catalysts that include a production rate hike decision on the Boeing 737, an option on the 767 wing modification program, and Q1 earnings.
  
• Wachovia upgraded Smith & Nephew (NYSE: SNN) based on growth opportunities, strong reconstruction product cycle, and potential share gains, among other reasons.

OTHER UPGRADES:

• UBS upgraded James River Coal Co. (NASDAQ: JRCC) based on higher long-term coal prices.
  
• Merriman upgraded Denny's Corp. (NASDAQ: DENN) because they believe that franchise growth initiative will reinvigorate the franchisees and put the company in a better position to beat estimates over the next year. The firm thinks investors need to refocus on the company's core operating profitability.

MOST NOTEWORTHY:

• Goldman downgraded shares of Washington Mutual (NYSE: WM), Freddie Mac (NYSE: FRE) and Fannie Mae (NYSE: FNM) to Sell from Neutral on concerns of significant credit losses from the housing market downturn.
  
• Motorola (NYSE: MOT) was lowered to Perform from Outperform at Oppenheimer after Q1 channel checks indicated a material shortfall in Q1 handset demand. They no longer see support for shares on a sum-of-the-parts valuation.
  
• Deutsche Bank downgraded shares of General Motors (NYSE: GM) to Hold from Buy as they believe the cyclical North American downturn could be deeper and more protracted than previously expected.
  

• Aventine Renwable (NYSE: AVR) was downgraded to Sell from Hold at Soleil.
  
• UBS lowered James River (NASDAQ: JRCC) and Peabody Energy (NYSE: BTU) to Neutral from Buy.
  
• Deutsche Bank lowered New York Times (NYSE: NYT) to Sell from Hold.