BOSTON ( TheStreet) -- The following companies have market capitalizations between $50 million and $500 million and "buy" ratings from our quantitative model, which considers more than 60 factors. They're ordered by their potential to appreciate, starting with the company with the best growth prospects. American Physicians Service Group ( AMPH) provides medical liability insurance and investment management services. The numbers: Second-quarter profit decreased 20% to $4.9 million, or 70 cents a share, as revenue declined 13% to $20 million. The company's gross margin fell from 58% to 44% and its operating margin dropped from 51% to 38%. The company has an ideal financial position, with $46 million of cash, compared to $6.5 million of debt. The stock: American Physicians Service Group is up 12% this year, matching the Dow Jones Industrial Average. The stock trades at a price-to-earnings ratio of 9, a discount to the market and insurance peers. Shares pay a 1.2% dividend yield.