Each weekday, TheStreet.com Ratings updates its ratings on the stocks it covers. The proprietary ratings model projects a stock's total return potential over a 12-month period, including both price appreciation and dividends . Buy, hold or sell ratings designate how the Ratings group expects these stocks to perform against a general benchmark of the equities market and interest rates . While the ratings model is quantitative, it uses both subjective and objective elements. For instance, subjective elements include expected equities market returns, future interest rates, implied industry outlook and forecast company earnings. Objective elements include volatility of past operating revenue, financial strength and company cash flows. Some recent rating changes are highlighted below. Motorola ( MOT) has been downgraded to hold from buy. The company provides wireless and broadband communication products worldwide. Motorola reported a net loss in the first quarter of fiscal 2007. The operating loss for the quarter was $366 million compared with a profit of $849 million during the same period a year ago. Profit margins declined drastically as the company cut prices and sold cheaper phones in emerging markets. Motorola had been rated a buy since March 2005.