Do you like gaining exposure to commodities? One way is through basic materials stocks. For ideas on how to find interesting basic materials stocks, we ran a screen.

We began by screening the basic materials sector for stocks that are technically oversold, with Relative Strength Index readings over the last 14 days below 40.

We then screened these names for those that also appear undervalued relative to the Graham Number, a measure of maximum fair value created by the "godfather of value investing" Benjamin Graham.

It is based off of a stock's EPS and book value per share (BVPS).

Graham Number = SQRT(22.5 x TTM EPS x MRQ BVPS)

The equation assumes that P/E should not be higher than 15 and P/BV should not be higher than 1.5. Stocks trading well below their Graham Number may be undervalued.

*Interactive Chart: Press Play to compare changes in market cap over the last two years for the top six stocks mentioned below. Analyst ratings sourced from Zacks Investment Research.*

Do you think these stocks are on the verge of a rebound? Use this list as a starting point for your own analysis.

List sorted by potential upside implied by the Graham Number.

** 1. Ultra Petroleum Corp. (UPL):** Engages in the acquisition, exploration, development, production, and operation of oil and natural gas properties in the United States. Market cap at $2.87B. Price at $18.22. RSI(14) at 27.46. Diluted TTM earnings per share at 2.94, and a MRQ book value per share value at 10.45, implies a Graham Number fair value = sqrt(22.5*2.94*10.45) = $26.29. Based on the stock's price at $19.00, this implies a potential upside of 38.38% from current levels.

** 2. Baker Hughes Incorporated (NYSE:BHI):** Supplies wellbore related products, and technology services and systems for drilling, formation evaluation, completion and production, and reservoir technology and consulting to the oil and natural gas industry worldwide. Market cap at $17.95B. Price at $40.92. RSI(14) at 35.24. Diluted TTM earnings per share at 3.97, and a MRQ book value per share value at 36.03, implies a Graham Number fair value = sqrt(22.5*3.97*36.03) = $56.73. Based on the stock's price at $41.05, this implies a potential upside of 38.2% from current levels.

** 3. ConocoPhillips (NYSE:COP):** Operates as an integrated energy company worldwide. Market cap at $92.80B. Price at $73.18. RSI(14) at 39.78. Diluted TTM earnings per share at 8.97, and a MRQ book value per share value at 50.73, implies a Graham Number fair value = sqrt(22.5*8.97*50.73) = $101.19. Based on the stock's price at $73.63, this implies a potential upside of 37.42% from current levels.

** 4. C&J Energy Services, Inc. Commo (NYSE:CJES):** Through its wholly-owned subsidiary, C&J Spec-Rent Services, Inc., provides specialty equipment services for oil and natural gas exploration and production companies in the Texas, Louisiana, and Oklahoma regions of the United States. Market cap at $880.55M. Price at $16.50. RSI(14) at 32.27. Diluted TTM earnings per share at 3.19, and a MRQ book value per share value at 7.61, implies a Graham Number fair value = sqrt(22.5*3.19*7.61) = $23.37. Based on the stock's price at $17.03, this implies a potential upside of 37.23% from current levels.

** 5. Newpark Resources Inc. (NYSE:NR):** Provides fluids management, waste disposal, and well site preparation products and services primarily to the oil and gas exploration and production industry. Market cap at $637.59M. Price at $6.99. RSI(14) at 31.93. Diluted TTM earnings per share at 0.8, and a MRQ book value per share value at 5.43, implies a Graham Number fair value = sqrt(22.5*0.8*5.43) = $9.89. Based on the stock's price at $7.46, this implies a potential upside of 32.52% from current levels.

** 6. Stone Energy Corp. (NYSE:SGY):** Engages in the acquisition, exploration, exploitation, development, and operation of oil and gas properties located in the Gulf of Mexico and Appalachia region. Market cap at $1.29B. Price at $26.24. RSI(14) at 35.13. Diluted TTM earnings per share at 3.97, and a MRQ book value per share value at 13.9, implies a Graham Number fair value = sqrt(22.5*3.97*13.9) = $35.24. Based on the stock's price at $26.72, this implies a potential upside of 31.87% from current levels.

* 7. OM Group Inc. (NYSE:OMG):* Develops, produces, and markets specialty chemicals, advanced materials, and electrochemical energy storage products worldwide. Market cap at $806.51M. Price at $24.86. RSI(14) at 34.89. Diluted TTM earnings per share at 1.21, and a MRQ book value per share value at 38.63, implies a Graham Number fair value = sqrt(22.5*1.21*38.63) = $32.43. Based on the stock's price at $25.3, this implies a potential upside of 28.18% from current levels.

** 8. Swift Energy Co. (NYSE:SFY):** Engages in developing, exploring, acquiring, and operating oil and natural gas properties in Louisiana and Texas. Market cap at $1.13B. Price at $26.86. RSI(14) at 37.42. Diluted TTM earnings per share at 2.28, and a MRQ book value per share value at 23.46, implies a Graham Number fair value = sqrt(22.5*2.28*23.46) = $34.69. Based on the stock's price at $27.64, this implies a potential upside of 25.51% from current levels.

** 9. Steel Dynamics Inc. (NASDAQ:STLD):** Engages in the manufacture and sale of steel products in the United States. Market cap at $2.87B. Price at $12.98. RSI(14) at 34.99. Diluted TTM earnings per share at 1.22, and a MRQ book value per share value at 10.58, implies a Graham Number fair value = sqrt(22.5*1.22*10.58) = $17.04. Based on the stock's price at $13.71, this implies a potential upside of 24.3% from current levels.

** 10. Stillwater Mining Co. (NYSE:SWC):** Engages in the development, extraction, processing, refining, and marketing of palladium, platinum, and associated metals in south central Montana, the United States. Market cap at $1.36B. Price at $11.50. RSI(14) at 33.27. Diluted TTM earnings per share at 1.3, and a MRQ book value per share value at 7.32, implies a Graham Number fair value = sqrt(22.5*1.3*7.32) = $14.63. Based on the stock's price at $11.89, this implies a potential upside of 23.07% from current levels.

** 11. Lone Pine Resources Inc. Common (LPR):** Engages in the exploration, development, and production of oil and gas properties in Alberta, British Columbia, Quebec, and the Northwest Territories of Canada. Market cap at $488.92M. Price at $5.67. RSI(14) at 19.83. Diluted TTM earnings per share at 0.44, and a MRQ book value per share value at 5.69, implies a Graham Number fair value = sqrt(22.5*0.44*5.69) = $7.51. Based on the stock's price at $6.18, this implies a potential upside of 21.45% from current levels.

*BVPS and EPS data sourced from Yahoo! Finance, all other data sourced from Finviz.

**Disclosure: **I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.