NEW YORK ( TheStreet) -- CHANGE IN RATINGS Assured Guaranty ( AGO) was downgraded at UBS to Neutral from Buy. $18 price target. Limited upside if Moody's downgrades, UBS said. American International ( AIG) was upgraded at Bernstein to Outperform. $45 price target. Company can continue to execute its final asset sales and soon be out from under the government's wings, Bernstein said. Brown-Forman ( BFB) was upgraded at UBS to Buy from Neutral. $98 price target. Multiple growth drivers behind revenue acceleration, UBS said. Biogen Idec ( BIIB) was upgraded at Goldman Sachs to Buy. $150 price target. Late-stage clinical pipeline remains attractive, Goldman said. Colony Financial ( CLNY) was downgraded to Hold at TheStreet Ratings. Cubist ( CBST) was initiated with a Hold rating at Brean Murray. Company lacks near-term catalysts, Brean Murray said. Celgene ( CELG) was initiated with a Buy rating at Cantor Fitzgerald. $90 price target. Company has multiple potential catalysts and can also deliver solid earnings growth over the next five years, Cantor said. Ciena ( CIEN) was upgraded at JP Morgan from Neutral to Overweight. $20 price target. Company is leveraged to the optical upgrade cycle, JP Morgan said. Gap ( GPS) was upgraded at Piper Jaffray to Overweight from Neutral. $34 price target. Company will benefit disproportionately from an emerging multiyear apparel cycle, Piper Jaffray said. Hologic ( HOLX) was initiated with a Buy rating at Bank of America/Merrill Lynch. $26 price target. New products can drive consistent, double-digit annual earnings growth, BofA/Merrill said. IBM ( IBM) was downgraded from Buy to Neutral at Bank of America/Merrill Lynch. Valuation call, based on a $215 price target, BofA/Merrill said. Joy Global ( JOY) was upgraded at Keybanc from Hold to Buy. Valuation call, based on a $90 price target, Keybanc said. Park-Ohio Holdings ( PKOH) was upgraded to Buy at TheStreet Ratings. Progressive ( PGR) was downgraded to Neutral from Buy at Bank of America/Merrill Lynch. $25 price target. Valuation call, BofA/Merrill said. Polaris ( PII) was downgraded at Wells Fargo from Outperform to Market Perform. Valuation call, Wells Fargo said. Spirit Airlines ( SAVE) was initiated with a Buy rating at Citigroup. $30 price target. Growth driven by increases in capacity and ancillary revenue, Citigroup said. Starbucks ( SBUX) was upgraded at Goldman Sachs from Neutral to Buy. Company was also placed on the Conviction List, as it appears to be entering a renewed growth phase, Goldman said.