BOSTON ( TheStreet) -- Here are three rating changes from TheStreet's stock model.3.The model upgraded Signet Jewelers ( SIG) to "hold." Quarter: Signet swung to a fourth-quarter profit of $117 million, or $1.36 a share, from a loss of $424 million, or $4.97, a year earlier. Revenue grew 7%. The operating margin rose from 10% to 13%. Signet has $316 million of cash and $324 million of debt. Stock: Signet Jewelers has almost tripled during the past year, outperforming U.S. indices. The stock trades at a price-to-book ratio of 1.4 and a price-to-cash-flow ratio of 4.7, representing 56% and 75% discounts to industry averages. Consensus: Of analysts covering Signet Jewelers, five recommend purchasing its shares and five advise holding them. Telsey Advisory Group expects the stock to gain 20% to $37. RBC Capital Markets and Bank of America ( BAC) are also bullish on Signet. 2. The model downgraded Cabot Oil & Gas ( COG) to "hold." Quarter: Fourth-quarter profit dropped 17% to $36 million, or 35 cents, as revenue inched up 0.4% to $233 million. The gross margin rose from 60% to 70% and the operating margin expanded from 17% to 27%. Cabot has $40 million of cash and $805 million of debt. Stock: Cabot Oil has risen 45% during the past year, lagging behind major benchmarks. The stock sells for a price-to-projected-earnings ratio of 33, a 140% premium to the industry average. It's cheap based on book value, sales and cash flow. Consensus: Of researchers evaluating Cabot Oil, 12 rate its stock "buy," 11 rate it "hold" and one says to "sell" it. SunTrust Robinson Humphrey projects a share price of $74, leaving room for the stock to double. Howard Weil is also optimistic about Cabot.