Petrohawk ( HK) rated new Neutral at Credit Suisse. Sees multiple years of strong production ahead but believes much of this is already reflected in stock price. Sets $18 target price. Koppers ( KOP) downgraded at UBS to Neutral rating from Buy. Price target and 2008 EPS estimates hold at $39 and $2.55, respectively. Monolithic Power ( MPWR) downgraded at Goldman Sachs to Neutral from Buy based on valuation. Stock reached $26 target yesterday, and shares are up 173% over the past 12 months. Company excellent growth prospects appear reflected in the multiple. Maxim Integrated ( MXIM) upgraded at Goldman Sachs to Buy from Neutral based on valuation. See likely "reversion effect" post Maxim's delisting from Nasdaq after stock's 20% underperformance this year. Note large valuation gap with ISIL despite similar earnings growth. Price target at $33. Mylan ( MYL) upgraded at JP Morgan from Neutral to Overweight. Company hosted an upbeat investor meeting, highlighting the ability to generate 30% to 35% earnings growth. Nucor ( NUE) initiated at Morgan Stanley with an overweight rating and $58 price target. Panera Bread ( PNRA) upgraded at JP Morgan from Neutral to Overweight. Stock looks attractive following the recent pullback, and the company can generate 20% earnings growth. Silicon Labs ( SLAB) downgraded at Citigroup from Buy to Hold. $44 price target. Stocks seems to be pricing in margin gains and the buyback program. US Steel ( X) initiated at Morgan Stanley with an underweight rating and $76 price target.