The following ratings changes were generated on Monday, Dec. 22.

We've upgraded AthenaHealth ( ATHN), which provides Internet-based business services for physician practices, from sell to hold. Strengths include its robust revenue growth, largely solid financial position with reasonable debt levels by most measures and notable return on equity. However, we also find weaknesses including premium valuation and a decline in the stock price during the past year.

Revenue rose by 35.4% since the same quarter a year ago, outperforming the industry average of 3.7% growth and boosting earnings per share. AthenaHealth's debt-to-equity ratio is very low at 0.1 and is currently below that of the industry average, implying very successful management of debt levels. The company also maintains a quick ratio of 4, which clearly demonstrates its ability to cover short-term cash needs.

Shares are down 14.6% on the year, in part reflecting the market's overall decline, but the stock is still selling for more than most others in its industry. We don't see anything in the company's numbers that may help reverse the decline experienced over the past 12 months.

We've downgraded Copel-CIA ( ELP), which generates, transmits and distributes electricity in Brazil, from buy to hold. Strengths include its largely solid financial position with reasonable debt levels by most measures, notable return on equity and attractive valuation levels. However, we also find weaknesses including unimpressive growth in net income, weak operating cash flow and poor profit margins.

Copel's debt-to-equity ratio is very low at 0.2 and is currently below that of the industry average, implying very successful management of debt levels. The company's 1.6 quick ratio demonstrates its ability of the company to cover short-term liquidity needs. Return on equity has improved slightly, which can be construed as a modest strength in the organization. On the basis of ROE, Copel outperforms the industry and the S&P 500.

Net income decreased by 48.3% compared with the same quarter a year ago, falling from $160.86 million to $83.18 million and underperforming both the S&P 500 and the electric utilities industry. Net operating cash flow has decreased to $165.57 million, or by 35.1%, and the firm's growth rate is much lower than the industry average. Revenue fell by 45.7%, significantly underperforming the industry average of 9.2%, and EPS declined.

We've downgraded uniform retailer Superior Uniform Group ( SGC) from buy to hold. Strengths include its revenue growth, largely solid financial position with reasonable debt levels by most measures and attractive valuation levels. However, we also find weaknesses including unimpressive growth in net income and a decline in the stock price during the past year.

Revenue increased by 0.7% since the same quarter a year ago, though EPS declined. The company's debt-to-equity ratio is very low at 0.06 and is currently below that of the industry average, implying very successful management of debt levels. SUG's 35.4% gross profit margin is strong, but it's 3.2% net profit margin trails the industry average. Net income decreased by 19.7%, dropping from $1.2 million to $1 million, underperforming the commercial services and supplies industry but outperforming the S&P 500.

Shares are down 27.8% on the past year, likely due in part to the decline of the overall market, which was sharper, as well as to SUG's weak EPS results. The stock's decline should not necessarily be interpreted as a negative; it could be one of the factors that may help make the stock attractive down the road. Right now, however, we believe that it is too soon to buy.

We've downgraded home heating oil distributor Star Gas Partners ( SGU) from hold to sell, driven by its feeble growth in its earnings per share, deteriorating net income, disappointing return on equity, poor profit margins and generally disappointing historical performance in the stock itself.

Net income fell to -$91.9 million in the most recent quarter from -$33.1 million in the same quarter a year ago, significantly underperforming the S&P 500 and the gas utilities industry. Return on equity has also greatly decreased since same quarter one year prior, a signal of major weakness within the corporation; on the basis of ROE, Star Gas also underperforms the S&P 500 and the industry average. The company's gross profit margin of 19.1% is rather low, though it has increased from the same period last year. Its net profit margin of -55.4% significantly underperformed the industry average.

EPS experienced a steep decline of 188.1% compared with the same quarter a year ago, continuing a two-year pattern of declining EPS. During the past fiscal year, Star Gas swung to a loss, reporting -17 cents vs. 51 cents in the prior year. Shares are down 41.2% on the year, reflecting the overall market decline as well as the company's decline in EPS. In one sense, the stock's 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

We've downgraded Tufco Technologies ( TFCO), which provides integrated manufacturing services, from hold to sell, driven by its generally disappointing historical performance in the stock itself, feeble growth in its earnings per share, deteriorating net income, disappointing return on equity and poor profit margins.

Net income decreased by 94.6%, from $520,000 to $30,000, since the same quarter a year ago, underperforming the S&P 500 and the commercial services and supplies industry. The company's current return on equity has slightly decreased from the same quarter one year prior, implying a minor weakness in the organization and underperforming the industry and the S&P 500. Tufco's 4.3% gross profit margin is extremely low, having decreased from the same quarter last year, and its net profit margin of 0.1% trails the industry average.

Tufco has experienced a steep decline in EPS or 90.9% in the most recent quarter compared with the same quarter a year ago, continuing a two-year pattern of declining EPS. During the past fiscal year, Tufco reported lower earnings of 13 cents versus 21 cents in the prior year. Shares are down 45.8% on the year, underperforming the S&P 500, but don't assume that the stock can now be tagged as cheap and attractive. Based on its current price in relation to its earnings, Tufco is still more expensive than most of the other companies in its industry.

All ratings changes generated on Dec. 22 are listed below.

Ticker
Company
Current
Change
Previous
ATHN
AthenaHealth
HOLD
Upgrade
SELL
CRR
Carbo Ceramics
HOLD
Downgrade
BUY
ELP
Copel
HOLD
Downgrade
BUY
FSI
Flexible Solutions International
HOLD
Upgrade
SELL
SGC
Superior Uniform Group
HOLD
Downgrade
BUY
SGU
Star Gas Partners
SELL
Downgrade
HOLD
TFCO
Tufco Technologies
SELL
Downgrade
HOLD

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.

If you liked this article you might like

Jim Cramer: These 4 Stocks Seem Attractive Right Here

Jim Cramer: These 4 Stocks Seem Attractive Right Here

Why Former General Electric CEO Jeff Immelt Is a Great Fit for Athenahealth

Why Former General Electric CEO Jeff Immelt Is a Great Fit for Athenahealth

Yes, the Stock Market Can Still Go Up in Smoke This Week

Yes, the Stock Market Can Still Go Up in Smoke This Week

Tesla CEO Elon Musk Doesn't Get One Thing About Being a CEO

Tesla CEO Elon Musk Doesn't Get One Thing About Being a CEO

Stocks Are Shaky, Tesla Posts Its Largest Loss Ever - 5 Things You Must Know

Stocks Are Shaky, Tesla Posts Its Largest Loss Ever - 5 Things You Must Know