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. New York Community Bancorp ( NYB), a financial services company, has been upgraded to buy. The company has shown strength in several areas, including revenue growth, good cash flow from operations, expanding profit margins, reasonable valuation levels and a solid stock price performance. These factors are expected to outweigh its somewhat disappointing return on equity. The bank's net operating cash flow increased by 97.5% in the second quarter to $162.58 million, while revenue growth greatly exceeded the industry average of 29.8%. During the second quarter, the company said net interest margin increased 12 basis points linked-quarter and 15 basis points year over year. New York Community Bancorp had been rated hold since July. Constellation Brands ( STZ), a beer, wine and spirits company, has been upgraded to buy. The company has enjoyed growth in earnings per share, reasonable valuation levels, good cash flow from operations, expanding profit margins and an increase in net income. These strengths should outweigh its generally poor debt management. EPS increased by 7.1% in the most recent quarter compared with the same quarter a year ago. Net operating cash flow increased by 237.3% to $263.80 million. Net income grew 5.4%, exceeding that of the beverages industry average, to $72.10 million. Sales after excise taxes dropped 37% to $892.6 million. Constellation Brands had been rated hold since July.