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.

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.

However, the rating does not incorporate all of the factors that can alter a stock's performance. For example, it doesn't always factor in recent corporate or industry events that could affect the stock price, nor does it include recent technology developments and competitive dynamics that may affect the company.

For those reasons, we believe a rating alone cannot tell the whole story, and that it should be part of an investor's overall research.

The following ratings changes were generated on Aug. 18.

We upgraded US Bancorp ( USB) to buy from hold. The Minneapolis, Minn.-based financial firm operates as a holding company for US Bank. This is driven by a few notable strengths, which we believe should have a greater impact than any weakness and should give investors a better performance opportunity than most stocks we cover.

Net operating cash flow has significantly increased by 248.21% to $1.560 billion when compared with the same quarter last year. Despite an increase in cash flow, US Bancorp's cash flow growth rate is still lower than the industry average growth rate of 270.18%.

The gross profit margin for USB is rather high; currently it is at 64.6%. Regardless of USB's high profit margin, it has managed to decrease from the same period last year. Despite the mixed results of the gross profit margin, US Bancorp's net profit margin of 19.4% compares favorably to the industry average.

USB, with its decline in revenue, underperformed when compared with the industry average of 15.2%. Since the same quarter, year over year, revenue slightly dropped by 4.2%. Weakness in the company's revenue seems to have hurt the bottom line, decreasing earnings per share.

The company's current return on equity has slightly decreased from the same quarter year over year. This implies a minor weakness in the organization. In comparison with the other companies in the Commercial Banks industry and the overall market, USB's return on equity significantly exceeds that of the industry average and is above that of the S&P 500.

The change in net income year over year has exceeded that of the S&P 500 but is less than that of the Commercial Banks industry average. The net income has decreased by 17.8% when compared year over year, dropping from $1.156 billion to $950 million.

USB had been rated a hold as of July 16, 2008.

Downgraded to hold from buy was Boeing ( BA). Based out of Chicago, Boeing designs and manufactures aircraft, satellites and other aeronautic devices. The primary factors that have impacted our rating are mixed -- some indicating strength, some showing weaknesses, with little evidence to justify the expectation of either a positive or negative performance for this stock relative to most other stocks.

Boeing's earnings per share declined by 14.1% in the most-recent quarter compared year over year. This company has reported somewhat volatile earnings recently but we feel it is poised for EPS growth in the coming year. During the past fiscal year, Boeing increased its bottom line by earning $5.25 vs. $2.84 in the prior year. This year, the market expects an improvement in earnings ($5.80 vs. $5.25).

Boeing, with its decline in revenue, slightly underperformed the industry average of 3.8%. Since the same quarter, one year prior, revenue slightly dropped by 0.4%. Weakness in the company's revenue seems to have hurt the bottom line, decreasing earnings per share.

Return on equity has greatly decreased when compared with its return on equity from the same quarter year over year. This is a signal of major weakness within the corporation. Compared with other companies in the Aerospace & Defense industry and the overall market, Boeing's return on equity significantly exceeds that of both the industry average and the S&P 500.

The gross profit margin for Boeing is rather low; currently it is at 20.3%. It has decreased from the same quarter year over year. Along with this, the net profit margin of 5% trails that of the industry average.

Net operating cash flow has significantly decreased to -$251.00 million, or 106.9%, when compared with the same quarter last year. In addition, in comparison with the industry average, the firm's growth rate is much lower.

Boeing had been rated a buy as of Aug. 18, 2006.

Petrohawk Energy ( HK) was downgraded to hold from buy. The Houston, Texas-based firm is an explorer of oil and natural gas properties in North America. The primary factors that have impacted our rating are mixed -- some indicating strength, some showing weakness, with little evidence to justify the expectation ofeither a positive or negative performance for this stock relative to most other stocks.

Petrohawk's revenue growth has slightly outpaced the industry average of 30.2%. Since the same quarter, year over year, revenue rose by 30.5%. This growth in revenue does not appear to have trickled down to the company's bottom line, displayed by a decline in earnings per share.

Compared with its closing price of one year ago, HK's share price has jumped by 86.91%, exceeding the performance of the broader market during that same time frame. Although HK had significant growth over the past year, our hold rating indicates that we do not recommend additional investment in this stock at the current time.

The gross profit margin for Petrohawk is currently very high, coming in at 87.10%. It has increased from the same quarter year over year. Regardless of the strong results of the gross profit margin, the net profit margin of - 30.50% is in-line with the industry average.

The company, on the basis of change in net income year over year, has significantly underperformed when compared with that of the S&P 500 and the Oil, Gas & Consumable Fuels industry. The net income has significantly decreased by 303.3% when compared with the same quarter one year ago, falling from $45.63 million to -$92.77 million.

Current return on equity is lower than its return on equity from the same quarter one year prior; this is a clear sign of weakness within the company. Compared with other companies in the Oil, Gas & Consumable Fuels industry and the overall market, Petrohawk Energy's return on equity significantly trails that of both the industry average and the S&P 500.

HK had been rated a buy as of April 3, 2007.

We downgraded Credit Suisse ( CS) to sell from hold. Based out of Zurich, Switzerland, the bank is a worldwide financial services company. The downgrade is driven by multiple weaknesses, which we believe should have a greater impact than any strengths and could make it more difficult for investors to achieve positive results compared with most of the stocks we cover.

Despite any intermediate fluctuations, we have only bad news to report on this stock's performance over the last year: It has tumbled by 31.56%, worse than the S&P 500's performance. Consistent with the plunge in the stock price, the company's earnings per share are down 50.44% compared year over year. Despite the heavy decline in its share price, this stock is still more expensive than most other companies in its industry.

The debt-to-equity ratio is very high at 21.65, currently higher than the industry average, implying that there is very poor management of debt levels within the company.

Return on equity has greatly decreased when compared with its return on equity from the same quarter year over year. This is a signal of major weakness within the corporation. When compared with other companies in the Capital Markets industry and the overall market, Credit Suisse's return on equity is below that of both the industry average and the S&P 500.

The change in net income from the same quarter, year over year, has exceeded that of the Capital Markets industry average, but is less than that of the S&P 500. The net income has significantly decreased by 52.5% when compared with the same quarter one year ago, falling from $2.558 billion to $1.214 billion.

CS has experienced a steep decline in EPS in the most-recent quarter in comparison with its performance from the same quarter a year ago. This company has reported somewhat volatile earnings recently. We feel it is likely to report a decline in earnings in the coming year. During the past fiscal year, Credit Suisse increased its bottom line by earning $6.15 vs. $5.93 in the prior year. For the next year, the market is expecting a contraction of 64.1% in earnings ($2.21 vs. $6.15).

CS had been rated a hold as of Sept. 11, 2007.

Tesoro ( TSO) was downgraded to a sell from hold. The San Antonio, Texas-based firm is a refiner of petroleum products in the U.S. This is driven by several weaknesses, which we believe should have a greater impact than any strengths and could make it more difficult for investors to achieve positive resultscompared with most of the stocks we cover.

Tesoro has experienced a steep decline in earnings per share in the most-recent quarter in comparison year over year. EPS has declined over the last year and we anticipate that this should continue in the coming year. During the past fiscal year, TSO reported lower earnings of $4.06 vs. $5.74 in the prior year. For the next year, the market is expecting a contraction of 106.4% in earnings (-26 cents vs. $4.06).

The company, on the basis of change in net income, year over year, has significantly underperformed when compared with that of the S&P 500 and the Oil, Gas & Consumable Fuels industry. The net income has significantly decreased by 99.1% when compared to year over year falling from $443.00 million.

Return on equity has greatly decreased when compared with its return on equity from the same quarter one year prior. This is a signal of major weakness within the corporation. Compared with other companies in the Oil, Gas & Consumable Fuels industry and the overall market, Tesoro's return on equity significantly trails that ofboth the industry average and the S&P 500.

The gross profit margin for Tesoro is currently extremely low, coming in at 2.2%. It has decreased significantly from the same period last year.

Net operating cash flow has decreased to $462.00 million, or 48.66%, when compared with the same quarter last year. In addition, in comparison to the industry average, the firm's growth rate is much lower.

TSO had been rated a hold as of Feb. 1, 2008.

Additional ratings changes from Aug. 18 are listed below.
Ticker Company Name Change New Rating Former Rating
ALSK Alaska Communications Systems Group Downgrade Hold Buy
ATLO Ames National Corp. Upgrade Buy Hold
BA Boeing Co. Downgrade Hold Buy
BMS Bemis Co. Upgrade Buy Hold
CBAK China BAK Battery Inc. Upgrade Hold Sell
CS Credit Suisse Downgrade Sell Hold
EMS Emergency Medical Services Corp. Upgrade Buy Hold
GTLS Chart Industries Inc. Upgrade Buy Hold
HK Petrohawk Energy Corp. Downgrade Hold Buy
IXSBF Innexus Biotech Corp. Initiated Sell
LIMS Starlims Technologies Ltd. Initiated Hold
MLI Mueller Industries Inc. Downgrade Hold Buy
NMRX Numerex Corp. Downgrade Sell Hold
OPLK Oplink Communications Inc. Upgrade Hold Sell
PBIP Prudential Bancorp Inc. of Pennsylvania Downgrade Sell Hold
SAM Boston Beer Co. Inc. Upgrade Buy Hold
TCK Teck Cominco Ltd. Downgrade Hold Buy
TGE TGC Industries Inc. Downgrade Hold Buy
TSO Tesoro Corp. Downgrade Sell Hold
USB US Bancorp Upgrade Buy Hold
WASH Washington Trust Bancorp Inc. Upgrade Buy Hold
WBSN Websense Inc. Upgrade Hold Sell
WSBC WesBanco Inc. Upgrade Buy Hold

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

More from Investing

Darden Restaurants Soars Following Blowout Earnings - Here's What to Know

Darden Restaurants Soars Following Blowout Earnings - Here's What to Know

Spotify: A Speculative Play for Sure

Spotify: A Speculative Play for Sure

Kroger Spikes as Sales Jump and Earnings Top Forecasts

Kroger Spikes as Sales Jump and Earnings Top Forecasts

Daimler's Profit Warning Should Terrify Traders Before Earnings Season Begins

Daimler's Profit Warning Should Terrify Traders Before Earnings Season Begins

Micron's Guidance and Commentary Calm Recent DRAM Fears

Micron's Guidance and Commentary Calm Recent DRAM Fears