Thursday's Analysts' Upgrades and Downgrades

Valueclick (VCLK Quote) downgraded at Citigroup from Buy to Hold. Valuation call, as the stock is within 3% of the $30 price target.

Xyratex (XRTX Quote) downgraded at Citigroup from Buy to Hold. $27 price target. Low-margin systems is the only business driver in the near term. Estimates also lowered.

STOCK COMMENTS / EPS CHANGES

Acergy (ACGY Quote) numbers raised at Jefferies. Price target lifts to $36 from $34 and FY 2008 EPS estimates upped to $1.85 from $1.80. Reiterates Buy rating.

United Health (UNH Quote) numbers raised at Jefferies. Price target lifts to $52 from $48 and FY 2007 EPS estimates upped to $3.51 from $3.48. Reiterates Buy rating.

Coca-Cola (KO Quote) numbers boosted at Citigroup. Now seen reaching $67. Estimates also raised, because of improved fundamentals in the Japanese business. Buy rating.

Life Time Fitness (LTM Quote) target raised at UBS. New price objective jumps to $75 from $63. Reiterates Buy rating.

Ruby Tuesday (RT Quote) target price cut at Credit Suisse to $22 from $30 based on "horrible" September results and outlook for next quarter. Believes there is value longer-term and reiterates Outperform rating.