BOSTON ( TheStreet) -- As fourth-quarter financial data streams and the stock market digests 2010's uncertain economic footing, our stock-rating model is shifting its view on select companies. Here are three pertinent ratings changes. 3. The model downgraded solar-panel maker SunPower ( SPWRA) to "sell." Investors are awaiting SunPower's fourth-quarter results. The numbers: Third-quarter net income tumbled 48% to $13 million, and earnings per share fell 55% to 13 cents, hurt by a higher share count. Revenue increased 24% to $466 million. SunPower's operating margin narrowed from 13% to 7.4%. The company holds $550 million of cash, equating to a quick ratio of 1.5. Its 0.5 debt-to-equity ratio demonstrates conservative leverage. The stock: SunPower recorded a 52-week low of $18.92 on Friday. The stock fell 46% during the past year, underperforming major U.S. indices and domestic competitor First Solar ( FSLR), which dropped 24% over the same period. SunPower shares are cheap relative to those of electrical-equipment peers based on projected earnings, book value and sales. They're expensive when considering cash flow. 2. The model upgraded property-and-casualty insurer CNA Financial ( CNA) to "hold." The numbers: CNA Financial swung to a fourth-quarter profit of $246 million, or 81 cents a share, from a loss of $336 million, or $1.31, a year earlier. Revenue increased 56% to $2.4 billion. CNA's operating margin hit16%. Its 0.2 debt-to-equity ratio is less than the industry average, indicating restrained leverage. The stock: CNA Financial soared 85% in the past year, outpacing major U.S. indices. The shares are cheap in comparison to those of insurance peers based on projected earnings, book value, sales and cash flow. They're costly when weighing trailing earnings. The stock has a beta, a measure of stock-market correlation, of 2.2, so it tends to magnify market swings.