Today was up most of the day but it felt choppy compared to yesterday's gains. A strong gas supply, a tick up in housing data, and a small decrease in weekly jobless claims all helped to offer a strong market for many sectors. Here were today's unofficial closing bell levels:

Dow Jones 10,320.10 +50.63 (0.49%)
S&P 500 1,090.10 +9.81 (0.91%)
Nasdaq 2,200.01 +23.17 (1.06%)

Traders on Wall Street are starting to place their bets that Mariner Energy (ME) is going to be one of the next stocks to fall to bearish trading pressure.

We know that they are placing their bets because Mariner's short interest is jumping through the roof.

Short interest is the current number of shares of a stock that have been sold short without being covered. And since traders typically only sell a stock short if they believe it is going to lose value, we know traders are growing increasingly bearish on Mariner.

Apache Corporation (APA) announced last week that it plans to acquire Mariner Energy Inc. (ME) in a $4 billion transaction. Typically when we see one company announce that it is going to acquire another company, the stock price of the company doing the acquiring goes down in the short term. But in the long term, this acquisition may help Apache's stock price break out.

Apache has been stuck in a consolidation range for a few months now. The stock price keeps bouncing back and forth between a slightly down-trending resistance level and an up-trending support level.

MOST NOTEWORTHY: Chipotle Mexican Grill, Micrus Endovascular and Acorda Therapeutics were today's noteworthy initiations:

• Jefferies expects the quality gap between Chipotle Mexican Grill (NYSE: CMG) and its peers will become more apparent in a weakening consumer environment. The firm started shares with a Buy rating and $110 target.
  
• Micrus Endovascular (NASDAQ: MEND) was initiated with an Outperform rating and $20 target at Barrington, citing the company's strong product line, improving salesforce, leading market share position and their expectation for continued strong transition from clipping to coiling.
  
• Acorda Therapeutics (NASDAQ: ACOR) was assumed with an Overweight rating at JP Morgan, as they believe the company's Fampridine-SR for multiple sclerosis is a $500M + opportunity

OTHER INITIATIONS:

• Stanford initiated Mariner Energy (NYSE: ME) with a Buy rating and $35 target.
  
• Deutsche Bank assumed Liberty Entertainment (NASDAQ: LMDIA) with a Buy rating and $29 target.
  
• EnerNoc (NASDAQ: ENOC) was initiated with a Neutral rating at Broadpoint.

MOST NOTEWORTHY: Air France, BHP Billiton, AstraZeneca, Broadcom and Savvis were today's noteworthy downgrades:

• Goldman removed shares of Air France (NYSE: AKH) from its Conviction Buy List due to the increase in the price of fuel and the possibility of an economic slowdown.
  
• Goldman downgraded BHP Billiton (NYSE: BHP) to Neutral from Buy and removed the stock from its Pan-Europe Buy List due to valuation.
  
• Merrill Lynch downgraded shares of AstraZeneca (NYSE: AZN) to Sell from Neutral to reflect increased competition from generic-drug makers, a poor pipeline and slow earnings growth.
  
• Wachovia downgraded shares of Broadcom Corporation (NASDAQ: BRCM) to Hold from Buy to reflect valuation and the company's lower than expected Q3 results. Shares were also lowered to Hold from Buy at Deutsche Bank.
  
• Stanford lowered Savvis (NASDAQ: SVVS) to Hold from Buy and notes that the company's Q3 results and Q4 revenue guidance brings the company's 2007 revenue outlook $15M below the consensus, and advises investors to remain on the sidelines. The firm believes the company's strategy is sound, but that its execution has been slow.

OTHER DOWNGRADES:

• Blockbuster (NYSE: BBI) and Akzo Nobel (OTC: AKZOY) were downgraded to Neutral from Overweight at JP Morgan.
  
• Friedman Billings downgraded the E&P sector, including Brigham Exploration Company (NASDAQ: BEXP), Mariner Energy (NYSE: ME) and Nobel Energy (NYSE: NBL) to Market Perform from Outperform.
  
• Baird downgraded Plantronics (NYSE: PLT) to Neutral from Outperform.
  
• Goldman downgraded Boston Scientific (NYSE: BSX) to Neutral from Buy.