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.