The following ratings changes were generated on Friday, Oct. 31. We've downgraded Chicago Bridge & Iron ( symbol), which operates as an engineering and procurement and construction company worldwide, from hold to sell, based on its deteriorating net income, disappointing return on equity, weak operating cash flow, generally disappointing historical performance in the stock itself and poor profit margins. Net income decreased by 85.4% when compared with the same quarter a year go, from $58.74 million to $8.55 million, significantly underperforming the S&P 500 and the construction and engineering industry. Return on equity has greatly decreased from the same quarter one year prior, trailing the industry average and the S&P 500. Net operating cash flow has significantly decreased to $29.01 million, or 76.55% when compared with the same quarter last year. In addition, the firm's growth rate is much lower than the industry average.Gross profit margin is extremely low at 12.8%, though it has increased from last year. Net profit margin of 0.50% trails the industry average. Shares tumbled by 76% on the year, worse than the S&P 500's performance. Consistent with the plunge in the stock price, the company's earnings per share are down 85.24% compared with the year-earlier quarter. Naturally, the overall market trend is bound to be a significant factor, and in one sense, the sharp decline last year is a positive for future investors, making it cheaper (in proportion to its earnings over the past year) than most other stocks in its industry. But due to other concerns, we feel the stock is still not a good buy right now.