BOSTON ( TheStreet) -- Here are four important upgrades from TheStreet's stock model.4. The model upgraded restaurant owner and franchiser Burger King ( BKC) to "buy." During the past three years, Burger King has boosted revenue 15% annually, on average, and profit 44% a year. Its stock posted declines over the same period. Quarter: Fiscal second-quarter profit increased 13% to $50 million, or 37 cents a share, as revenue inched up 1.8% to $645 million. The operating margin remained steady at 14%. Burger King holds $140 million of cash and $859 million of debt. Stock: Burger King has dropped 12% in the past 12 months, lagging behind U.S. indices. The stock trades at a price-to-projected-earnings ratio of 14 and a price-to-book ratio of 2.6, reflecting 53% and 55% discounts to peer-group averages. Consensus: Of analysts covering Burger King, six, or 32%, advise purchasing its shares and 13 recommend holding them. Deutsche Bank and Piper Jaffray expect the stock to hit $24, implying a potential 18% gain in the weeks ahead. 3. The model upgraded used-vehicle retailer CarMax ( KMX) to "buy." During the past three years, CarMax's revenue has stagnated, but net income has risen 8.1% annually. Its return on equity, a profitability measure, trails the industry average. Quarter: CarMax swung to a fiscal third-quarter profit of $75 million, or 33 cents, from a loss of $22 million, or 10 cents, a year earlier. Revenue jumped 24%. The operating margin turned positive. CarMax holds $15 million of cash and $147 million of debt. Stock: CarMax nearly doubled during the past year, beating major benchmarks. The stock sells for a PEG ratio, a measure of value relative to expected long-term growth, of 0.1, a 93% discount to the industry average. A PEG ratio below 1 signifies a bargain. Consensus: Of researchers evaluating CarMax, four rate its stock "buy," 11 rate it "hold" and one ranks it "sell." Rochdale Securities expects the stock to advance 22% to $30. Less-bullish Bank of America projects a future share price of $28.
2. The model upgraded St. Jude Medical ( STJ) to "buy." St. Jude makes equipment for the human heart, including pacemakers, replacement valves and repair products. Its stock has risen 9.8% in the past three months, beating U.S. indices. Quarter: St. Jude swung to a fourth-quarter profit of $190 million, or 57 cents, from a loss of $201 million, or 58 cents, a year earlier. Revenue rose 6.3%. The operating margin extended to 29%. St. Jude holds $393 million of cash and $1.9 billion of debt. Stock: St. Jude has climbed 7.4% during the past 12 months, trailing U.S. indices. The stock trades at a PEG ratio of 0.8, a 34% discount to the industry average and a bargain relative to projected long-term growth. It's also cheap based on sales. Consensus: Of analysts rating St. Jude, 21, or 62%, suggest purchasing shares, 11 advise holding and two say to sell them. Soleil Securities and JPMorgan value each share at $48, leaving a potential 18% gain. The stock has jumped 10% in three months. 1. The model upgraded chipmaker Marvell Technology ( MRVL) to "buy." It designs analog, mixed-signal and embedded microprocessor circuits. During the past three years, Marvell Technology has tripled net income annually, on average. Quarter: Marvell swung to a fourth-quarter profit of $205 million, or 31 cents, from a loss of $65 million, or 11 cents, a year earlier. Revenue soared 64%. The operating margin rose to 25%. Marvell holds $1.8 billion of cash and $2.5 million of debt. Stock: Marvell Technology has more than doubled in the past year, outperforming major benchmarks. The stock sells for a PEG ratio of 0.2, a 61% discount to the peer-group average and a bargain when considering expected growth rates. Consensus: Of firms following Marvell, 29, or 85%, rate its stock "buy" and five rate it "hold." JMP Securities and Pacific Crest Securities predict a future share price of $30, implying a potential 44% upside. Marvell has risen 8% in the past month. Visit Stockpickr's Ratings Upgrades Portfolio and Ratings Downgrades Portfolio