The following ratings changes were generated on Thursday, Oct. 23. We've downgraded Cisco Systems, designs, manufactures and sells IP-based networking products, from buy to hold. Strengths include its revenue growth, largely solid financial position with reasonable debt levels by most measures and growth in earnings per share. However, the stock has had a generally disappointing performance in the past year. Revenue growth of 9.9% since the same quarter one year ago greatly exceeded the industry average of 27.7%, improving EPS. Cisco's 0.20 debt-to-equity ratio is very low but is nonetheless higher than the industry average. Its quick ratio of 2.23 demonstrates an ability to cover short-term liquidity needs. Return on equity has improved slightly over the same quarter last year, outperforming the S&P 500 but underperforming the communications equipment industry. Gross profit margin of 67% is rather high but has decreased since the same period last year. Net profit margin of 19.4% compares favorably to the industry average. Shares have plunged by 44.51% on the year. Naturally, the overall market trend is bound to be a significant factor, and the stock's sharp decline last year could be a positive for future investors, making it cheaper (in proportion to its earnings over the past year) than most other stocks in its industry. However, we feel the stock is still not a good buy right now. We've downgraded science and technology company DuPont ( DD) from buy to hold. Strengths include its revenue growth, reasonable valuation levels and largely solid financial position with reasonable debt levels by most measures. Weaknesses include deteriorating net income, poor profit margins and weak operating cash flow.