OV / UN Valued: 12 oil services stocks are undervalued with Transocean ( RIG) the most undervalued by 13.9%. The most overvalued stock is Oil States International ( OIS) by 24.7%. VE Rating: Tenaris ( TS) is the only stock in the table with a "4-Engine" buy rating after being upgraded from hold this morning. McDermott International ( MDR) was upgraded to hold from sell. Tidewater ( TDW) is only "2-Engine" sell rated stock in the table. All other stocks in the table have "3-Engine" or hold ratings. Patterson-UTI Energy ( PTEN) has been downgraded to hold from buy this morning. Last 12-Month Return (%): 12 oil services stocks declined over the last 12 months with Weatherford ( WFT) the biggest loser down 20.2%. The biggest winner of the 12 risers is Patterson-UTI Energy with a gain of 29.6%. Forecast 1-Year Return: The biggest potential loser is Tidewater with a projected loss of 7.6% over the next 12 months. The projected winners are expected to be up only slightly between 0.5% and 4.7%. 12 Month Trailing P/E Ratios: P/E ratios range from 10.1 for Oil States to 28.7 for Core Labs ( CLB). 200-Day Simple Moving Averages: We began the week with only two oil services stocks below their 200-day SMAs. The reversion to the mean spread to four additional names this week. Those below are; Diamond Offshore ( DO), McDermott ( MDR), Noble ( NE), National Oilwell ( NOV), Rowan Companies ( RDC), and Seadrill ( SDRL). This means that the other 19 stocks are still at risk of reversion to the mean. Here's how to use the Value Levels and Risky Levels for stocks in today's table: Value Level: is the price at which to enter a GTC Limit Order to buy on weakness. The letters mean; W-Weekly, M-Monthly, Q-Quarterly, S-Semiannual and A- Annual. Pivot: A level between a value level and risky level that should be a magnet during the time frame noted. Risky Level: is the price at which to enter a GTC Limit Order to sell on strength. The author has no positions in the stocks mentioned today.Follow @suttmeierThis article was written by an independent contributor, separate from TheStreet's regular news coverage.