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 company earnings forecasts. Objective elements include volatility of past operating revenue, financial strength and company cash flows.

Western Refining

(WNR)

, an independent crude oil refiner, has been upgraded to hold. While the company has enjoyed notable return on equity, robust revenue growth and attractive valuation levels, its debt management and profit margins have been poor. The company earned $155.0 million, or $2.29 a share, for the second-quarter, up from $86.5 million, or $1.29 a share, a year ago. Powered by its strong earnings growth and other factors, Western Refining's stock has surged by 50.6% over the past year, but TheStreet.com Ratings does not recommend additional investment in this stock despite these gains. Western Refining had been rated sell since February.

Thornburg Mortgage

( TMA), a single-family residential mortgage lending company, has been downgraded to sell. The company's weaknesses can be seen in several areas, such as its feeble EPS growth, deteriorating net income, weak debt management, disappointing return on equity and generally unsatisfactory historical stock performance. Thornburg recently reported a third-quarter loss of $1.09 billion, or $8.83 a share, compared with earnings of $72.9 million, or 64 cents a share, a year earlier. EPS has declined over the last two years and this is expected to continue in the coming year. The stock has tumbled 62.6% over the last year and return on equity greatly decreased from a year ago. Thornburg Mortgage had been rated hold since October 2006.

Regions Financial

(RF) - Get Report

, a financial services company, has been downgraded to hold. The company has enjoyed robust revenue growth, attractive valuation levels and an increase in net income. However, the performance of its stock price and return on equity have been disappointing, while EPS growth has been feeble. Regions Financial recently reported third-quarter earnings of $394.2 million, or 56 cents a share, up 12.1% from a year ago. Excluding merger-related costs, the company earned 64 cents a share. Revenues leaped by 51.9%. Over the last year, the company's stock price tumbled 30.6% and return on equity has slightly decreased from a year ago. Regions Financial had been rated buy since October 2005.

Radvision

( RVSN), an Israeli maker of video conferencing systems, has been downgraded to hold. The company has enjoyed revenue growth while maintaining a largely solid financial position with reasonable and valuation levels. However, Radvision has also been marked by unsatisfactory return on equity, weak operating cash flow and a the performance of the stock itself has been generally disappointing. The company reported second-quarter earnings of $3.63 million, or 16 cents a share, up from $3.21 million, or 14 cents a share, a year ago. Revenue totaled $24.7 million, up from $22 million a year ago. Return on equity has slightly decreased from the same quarter one year prior and comes in below the industry average. Net operating cash flow has significantly decreased 428.15% from a year ago. Earlier this month, Radvision lowered its forecast for third-quarter revenue. It is due to report results for the quarter on Nov. 1. Radvision had been rated buy since October 2005.

Hugoton Royalty Trust

(HGT)

, an energy income trust, has been downgraded to hold. The company maintains a largely solid financial position with reasonable debt levels, revenue growth and expanding profit margins, but the stock price performance has been disappointing and EPS growth has been feeble. Hugoton Royalty Trust has reported somewhat volatile earnings recently and it is likely to report an earnings decline in the coming year. The stock has declined 6.7% from its price level of one year ago. Outside of the push or pull of the broad market, there is nothing in the company's numbers that may help reverse the decline experienced over the past 12 months. Hugoton Royalty Trust had been rated buy since October 2005.

Additional ratings changes are listed below.