BOSTON (TheStreet) -- Stocks fell from a 10-week high yesterday on renewed concern about slower economic growth. But the performance of riskier assets demonstrates confidence in a continuous economic expansion. Here are 10 speculative small-cap stocks that made huge gains in July. They are ordered by monthly return, from big to biggest.

10. Lithia Motors ( LAD) has advanced 34% in the past month. Lithia operates automotive franchises. It swung to a second-quarter loss of $1.7 million, or 6 cents a share, from a profit of $3.7 million, or 12 cents, a year earlier. But revenue grew 20% and adjusted profit increased 23%. Also, same-store sales, a crucial metric for retailers, jumped 26% for new vehicles and 15% for used vehicles. Lithia shares sell for a forward earnings multiple of 8.4, a 42% discount to the automotive industry average. JPMorgan ( JPM) and Stephens rate the stock "hold", but both value it at $10, implying 17% of upside.

9. Star Scientific ( CIGX) has returned 39% in the past four weeks. Star develops and licenses curing technologies that prevent the formation of carcinogenic toxins in tobacco. Star has posted losses for nine consecutive quarters. Its second-quarter loss narrowed to $4.9 million, or 4 cents, from $5.2 million, or 6 cents, a year earlier. Star filed applications with the FDA on Feb. 19 and Jun. 21 for Stonewall BDL and ARIVA-BDL, two "modified-risk" tobacco products. They are dissolvable tobacco lozenges, meant to be substitutes for cigarettes, snuff or pouches, with much less nitrosamine, a prevalent carcinogen.

8. Ramtron ( RMTR) has gained 42% in the past month. Ramtron designs memory, microcontroller and integrated semiconductors. It swung to a second-quarter profit of $360,000, or 1 cent per share, from a loss of $300,000, or 1 cent, a year earlier. Revenue soared 66% and the operating margin climbed from the negatives to 3.8%. Product revenue jumped 74%. Ramtron's shares sell for a price-to-book ratio of 2.8 and a price-to-sales ratio of 1.6, 50% and 54% discounts to semiconductor peer averages. Just one firm, Blaylock Robert Van, covers Ramtron, rating it "buy" with a target of $6.20, implying a 75% return.

7. Infinera ( INFN) has risen 43% in the past four weeks. Infinera designs optical networking systems, using proprietary photonic integration technology. It sells its products to telecom, cable and Internet content companies. Infinera's second-quarter loss narrowed 65% to $9.6 million, or 10 cents, from a loss of $27 million, or 28 cents, a year earlier. Revenue grew 62% and the gross margin extended from 35% to 46%. Infinera's stock trades at a forward earnings multiple of 20, a premium to peers' shares. Eight, or 67%, of analysts covering Infinera rate its stock "buy." Citigroup ( C) predicts it will rise 15% to $10.50.

6. Westlake Chemical ( WLK) has advanced 44% in the past month. Westlake manufactures olefins and vinyls. Second-quarter profit more than tripled to $57 million, or 86 cents a share, as sales increased 42%. The olefins segment generated income of $111 million from operations, whereas the vinyls segment suffered a loss of $11 million. Westlake shares sell for a PEG ratio, a measure of value relative to predicted long-run growth, of 0.4, a 60% discount to estimated fair value. They are expensive based on trailing earnings and cash flow. Just two, or 22%, of researchers covering Westlake rate its stock "buy."

5. Sun Bancorp ( SNBC) has soared 48% in the past four weeks. Sun offers retail and commercial banking services in New Jersey, Delaware and Pennsylvania. Its second-quarter loss multiplied to $81 million, or $3.46 a share, from a loss of $4.6 million, or 38 cents, a year earlier. Revenue ascended 4.4%. On July 8, Sun announced that it plans to sell a 25% stake in its company, in common and preferred stock, to private equity funds associated with WL Ross and a major shareholder for $100 million. Of analysts covering Sun, four, or 66%, rate its stock "buy." A median target of $6.15 suggests another 16% of upside.

4. MBIA ( MBI) has surged 55% in the past month. MBIA provides financial guarantee insurance, primarily for fixed-income securities, including municipal debt and mortgage-backed securities. It suffered considerable losses as a result of the subprime meltdown. The company has posted losses in six of its past nine quarters. It is scheduled to report second-quarter results Aug. 9. It swung to a first-quarter loss of $1.5 billion, or $7.22, from a profit of $697 million, or $3.34, a year earlier. Mutual fund company Fairholme Capital, run by value investor Bruce Berkowitz, recently disclosed an 11% stake in MBIA.

3. Stoneridge ( SRI) has rallied 57% in the past four weeks. Stoneridge sells electronic components for trucks, agricultural equipment and automobiles. It swung to a second-quarter profit of $4.2 million, or 17 cents a share, from a loss of $20 million, or 84 cents, a year earlier. Revenue grew 63% and the operating margin stretched from the negatives to 4.9%. The stock trades at a forward earnings multiple of 8.6 and a sales multiple of 0.5, 77% and 65% discounts to auto peer averages. KeyCorp ( KEY) is the lone bull of the three researchers following Stoneridge. It offers a $16 target, implying a 43% return.

2. Atlas Pipeline Partners ( APL) has soared 86% in the past month. Atlas is a master limited partnership, a company with a unique tax structure, similar to a REIT, designed to pay large distributions to its shareholders. Atlas transports and processes natural gas. Second-quarter gross profit rose 65% to $69 million and adjusted EBITDA increased 21% to $47 million. On Monday, Barclays ( BCS) upgraded Atlas to "overweight" and raised its target to $19, implying 6% of upside, citing financial flexibility to invest in the Marcellus shale. Citigroup ranks Atlas "buy" and expects the stock to rise 23% to $22.

1. Industrial Services of America ( IDSA) has surged 91% in the past four weeks. Industrial Services offers waste- and recycling-management services to commercial customers. It specializes in the recycling of ferrous and non-ferrous metals. The company recently secured a $49 million line of credit from Fifth Third Bancorp ( FITB). It hasn't yet released second-quarter results. But during the past three years, Industrial Services has increased revenue 52% annually, on average, and boosted net income 170% a year. Just one brokerage, Taglich Brothers, follows the stock, which has passed the $18 target.

-- Reported by Jake Lynch in Boston.

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