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BOSTON ( TheStreet) -- TheStreet.com's stock-rating model upgraded Chipotle Mexican Grill ( CMG - Get Report) to "buy."

The numbers: Second-quarter net income increased 45% to $35 million and earnings per share climbed 49% to $1.10, boosted by a lower share count. Revenue grew 14% to $389 million. Its gross margin rose from 22% to 26% and its operating margin increased from 12% to 15%. A quick ratio of 2.7 demonstrates ample liquidity. The company holds minimal debt.

The numbers: Chipotle is up 49% this year, outpacing major U.S. indices. The stock trades at a price-to-earnings ratio of 31, a premium to the market and restaurant peers. The company doesn't pay dividends.

The model upgraded oil-and-gas partnership BreitBurn Energy ( BBEP) to "hold."

The numbers: The company's second-quarter loss narrowed to $109 million, or $2.06 a share, from a loss of $286 million, or $4.39 a share, in the year-earlier period. The company has a less-than-ideal liquidity position, evident in its quick ratio of 0.7. A debt-to-equity ratio of 0.5 reflects conservative leverage.

The stock: BreitBurn is up 75% this year, beating major U.S. indices. The stock trades at a price-to-earnings ratio of 1, a discount to the market and oil-and-gas peers. The company has a history of erratic operating results.

The model upgraded semiconductor-equipment maker MKS Instruments ( MKSI - Get Report) to "hold."

The numbers: The company swung to a second-quarter loss of $207 million, or $4.20 a share, from a profit of $9.2 million, or 18 cents a share, in the year-earlier period. Revenue dropped 54% to $79 million. Its gross margin fell from 43% to 37% and its operating margin fell into negative territory. The company has an ideal financial position, with $259 million of cash and no debt.

The stock: MKS Instruments has advanced 32% this year, beating the Dow Jones Industrial Average and S&P 500 Index. The company has posted losses for three consecutive quarters. The stock doesn't pay dividends.

The model upgraded oil-and-gas driller Pride International ( PDE) to "buy."

The numbers: Second-quarter net income fell 34% to $124 million and earnings per share fell 21% to 69 cents. Revenue deteriorated 8% to $501 million. Its gross margin fell from 50% to 46% and its operating margin dropped from 33% to 29%. A quick ratio of 2.9 demonstrates ample liquidity. A debt-to-equity ratio of 0.3 indicates modest leverage.

The stock: Pride International has advanced 90% this year, more than major U.S. indices. The stock trades at a price-to-earnings ratio of 8, a discount to the market and drilling peers. The company doesn't pay dividends.

The model upgraded thrift and mortgage finance company TFS Financial ( TFSL - Get Report) to "hold."

The numbers: Fiscal third-quarter net income jumped 48% to $10 million and earnings per share climbed 50% to 3 cents, boosted by a lower share count. Revenue dropped 3% to $139 million. Its gross margin rose from 35% to 43% and its operating margin increased from 17% to 19%. The company is well-capitalized, with $173 million of cash, compared to $190 million of debt.

The stock: TFS Financial has fallen 8% this year, lagging behind major U.S. indices. The stock trades at a price-to-earnings ratio of 88, a premium to the market and financial peers. Shares pay a 2.4% dividend yield.

-- Reported by Jake Lynch in Boston.