Tuesday's Analysts' Upgrades and Downgrades

CHANGE IN RATINGS

Aeropostale (ARO Quote) was downgraded from Buy to Neutral at Merrill Lynch. Strong second-quarter earnings are already priced into the stock, which has just moved through the $47 price target.

Elan (ELN Quote) was upgraded to Hold at Citigroup. $21 price target. New Alzheimer's drug could be a potential blockbuster product, reaching the market in about two years.

MGM Mirage (MGM Quote) target price raised at Goldman to $85 from $65 based on sum of parts analysis following latest Tracinda offer. Maintined Neutral rating.

MGM Mirage upgraded from Peer Perform to Outperform at Bear Stearns. $95 price target. Tracinda announcement should help unlock value from the company.

Marathon Oil (MRO Quote) was upgraded from Hold to Buy at AG Edwards. The energy sector is once again leading the market higher, but the market only appears to be discounting oil at $48 a barrel.

Olin (OLN Quote) was upgraded to Buy at Merrill Lynch. Pioneer purchase should immediately add to earnings. $24 price target. New scale and increased profitability in the chlor-alkali business could also allow the company to exit lower margin areas.

Shaw Group (SGR Quote) was upgraded from Neutral to Buy at Merrill Lynch. $47 price target. Stock has doubled over the past year, but the company remains a play on the coal and nuclear construction cycles.