Each weekday, TheStreet.com Ratings compiles a list of the top five stocks in five categories -- fast-growth, all-around value, large-cap, mid-cap and small-cap -- and publishes these lists in the Ratings section of our Web site .

This list, updated daily, is based on data from the close of the previous trading session. Today, mid-cap stocks are in the spotlight. These are stocks of companies that have market capitalizations of between $500 million and $10 billion that rank near the top of all stocks rated by our proprietary quantitative model, which looks at more than 60 factors.

The stocks must also be followed by at least one financial analyst who posts estimates on the Institutional Brokers' Estimate System. They are ordered by their potential to appreciate.

Note that no provision is made for off-balance-sheet assets such as unrealized appreciation/depreciation of investments, market value of real estate or contingent liabilities that might affect book value. This could be material for some companies with large underfunded pension plans.

AptarGroup ( ATR) manufactures and sells dispensing systems to the personal care, cosmetic, pharmaceutical and food/beverage markets worldwide. It has been rated a buy since October 2005. Third-quarter revenue increased 19.9% over a year ago to $485.69 million, powered by strong sales, favorable exchange-rate movements and acquisitions. These factors, along with lower net interest expense and lower tax rates, boosted net income by 39.5% to $39.48 million for the quarter.

AptarGroup also implemented a share buyback program authorizing the repurchase of about $19.70 million worth of stock during the fourth quarter. In addition to noting its notable financial performance, TheStreet.com Ratings is encouraged by the company's solid fourth-quarter earnings outlook, its initiatives to increase shareholder returns and its strong balance sheet.

However, AptarGroup operates in markets that are highly competitive, especially in regard to price. This, along with increasing raw-material costs over the past few years, could affect the company's operating results.

Goodrich ( GR), which supplies aerospace and defense security products, has been rated a buy since August 2005. Third-quarter earnings grew 25.9%, driven by commercial aircraft equipment sales. Net income increased to $126.80 million, or 99 cents a share, for the quarter. (Excluding items, earnings for the quarter were $1.10 a share, which beat the consensus estimate of 91 cents a share.)

Third-quarter revenue rose 14.8% to $1.40 billion compared with the same period last year, and the company's overall operating margin rose to 17.23% from 14.47% in a year earlier. During the quarter, Goodrich declared a dividend of 20 cents a share. Goodrich agreed to sell its Aviation Technical Services business to Macquarie Bank for about $90 million.

Any decline in government spending and the weakened condition of the airline industry are among the downside risks.

Greif ( GEF) manufactures and distributes industrial packaging products. It has been rated buy since November 2005. The company maintains a largely solid financial position with reasonable debt levels, robust revenue and EPS growth and a solid stock price performance. These strengths should outweigh the company's low profit margin.

Third-quarter revenue climbed 27% over a year ago to $874.2 million, outpacing the industry average of 19.2%. EPS increased 25.6% over the same period. Greif has demonstrated a pattern of positive EPS growth over the past year and this trend is expected to continue. Return on equity has improved slightly when compared with the same quarter one year prior.

On the whole, the containers and packaging industry has performed reasonably well since the U.S. economy emerged from recession in the early part of the decade, but threats to profitability abound, depending on product mix and end-market exposure.

FMC ( FMC), a chemical company, has been rated buy since November 2005. The company has a largely solid financial position with reasonable debt levels, a solid stock price performance, good cash flow from operations, along with EPS and revenue growth. These strengths are expected to outweigh the fact that the company has had somewhat disappointing return on equity. Third-quarter profit totaled $37.1 million or 48 cents a share, up from $35.1 million, or 44 cents a share, a year ago. Revenue increased nearly 10% over a year ago to $626.6 million.

Investors have apparently begun to recognize FMC's positive factors, as the company's shares are up 62.56% over the past year. The stock's sharp rise has already helped drive it to a level which is relatively expensive compared to the rest of its industry, but TheStreet.com Ratings feels that other strengths FMC displays justify these higher price levels. The two most critical factors impacting the financial health of chemical companies are the costs of raw materials (mainly oil and gas) and the overall strength of the economy.

Range Resources ( RRC) engages in the exploration, development and acquisition of oil and gas properties primarily in the Southwestern, Appalachian and Gulf Coast regions of the U.S. It has been rated a buy since November 2005. The company's third-quarter earnings climbed 15% on the year to $58.9 million, or 39 cents a share. Excluding items, Range Resources earned $64.4 million, or 42 cents a share. Revenue increased 10% to $242.4 million.

Range Resources is expected to continue to benefit from a favorable industry outlook. The company is aggressively pursuing its drilling and acquisition programs even at the cost of raising more debt. However, oil exploration is risky, and the current success rate may not continue. Moreover, oil and gas prices are highly volatile and cyclical in nature, and are already trading at 12-month highs. Any downtrend may affect profitability.