Each business day, 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.

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F5 Networks ( FFIV - Get Report), through its subsidiaries, develops, markets and sells products that help customers manage application traffic on Internet-based networks. The company has been downgraded to a hold from a buy.

The company's fourth-quarter revenue rose by 30.3% compared with the same period last year, though this lagged the industry average of 39%. F5 has no debt to speak of, a relatively favorable sign. In addition, F5's quick ratio of 2.28 demonstrates the company's ability to cover short-term liquidity needs.

However, the company's net income fell by 27.4% to $12.88 million, or 15 cents a share, in the fourth quarter, compared with $17.75 million, or 22 cents per share in the same period last year. The company's stock price has fallen by 41.08% in the last 12 months, and its return on equity decreased in the fourth quarter from the same quarter one year prior. This implies a major weakness in the organization. F5 had been rated a buy since coverage was initiated in January 2006.

Industrial Services of America ( IDSA - Get Report) sells package waste and recycling management services to commercial, industrial and logistic customers in North America. It has been downgraded to a hold from a buy.

The company's third-quarter revenue rose by 16.9% compared with the same period last year, outpacing the industry average of 0.8%. Its low debt-to-equity ratio of 0.66 is below that of the industry average, implying that there has been a relatively successful effort in the management of debt levels.

In addition, Industrial Services of America sports an adequate quick ratio of 1.42, which illustrates the ability to avoid short-term cash problems. Weaknesses include a 12.7% drop in net income in the third quarter to $380,000 from $440,000 in the same period last year. In addition, the company displays poor profit margins and weak operating cash flow. Industrial Services of America had been rated a buy since June 2007.

Werner Enterprises ( WERN - Get Report) hauls truckload shipments of general commodities through two segments: truckload transportation services and value-added services. It has been downgraded to a hold from a buy.

Among the primary strengths of the company is its solid financial position based on a variety of debt and liquidity measures that we have evaluated. Werner's third-quarter earnings slipped to 30 cents per share from 31 cents a share in the same period last year, continuing a pattern of somewhat volatile earnings recently. The company's gross profit margin came in at 14.2% in the third quarter, having decreased from the same period last year. Along with this, its net profit margin of 4.3% trails the industry average. Werner Enterprises had been rated a buy since coverage was initiated in January 2006.

This article was written by a staff member of TheStreet.com Ratings.