Gainers

• Semgroup, Inc. (NYSE:SEMG) stock increased by 64.1% to $16.85 during Monday's pre-market session. The market cap stands at $1.1 billion. The most recent rating by RBC Capital, on August 23, is at Sector Perform, with a price target of $11.00.
• Denbury Resources, Inc. (NYSE:DNR) shares increased by 31.7% to $1.60. The market cap seems to be at $1.0 billion.
• California Resources, Inc. (NYSE:CRC) shares rose 29.4% to $15.30. The market cap seems to be at $717.1 million. The most recent rating by Bank of America, on July 23, is at Neutral, with a price target of $24.00.
• Zion Oil & Gas, Inc. (NASDAQ:ZN) shares rose 26.8% to $0.36. The market cap seems to be at $58.7 million.
• Chaparral Energy, Inc. (NYSE:CHAP) stock increased by 25.7% to $2.15. The market value of their outstanding shares is at $585.0 million.
• Key Energy Services, Inc. (NYSE:KEG) shares increased by 24.3% to $1.84. The market cap seems to be at $1.2 billion.
• Extraction Oil & Gas, Inc. (NASDAQ:XOG) shares increased by 23.5% to $3.99. The market cap seems to be at $3.4 billion. The most recent rating by Barclays, on August 30, is at Underweight, with a price target of $4.00.
• W&T Offshore, Inc. (NYSE:WTI) stock rose 23.1% to $5.70. The market cap stands at $942.0 million.
• Whiting Petroleum, Inc. (NYSE:WLL) shares rose 22.2% to $9.20. The market cap seems to be at $1.5 billion. The most recent rating by Bank of America, on September 10, is at Neutral, with a price target of $11.00.
• SAExploration Holdings, Inc. (NASDAQ:SAEX) stock moved upwards by 20.1% to $2.33. The market value of their outstanding shares is at $13.3 million.
• Chesapeake Energy, Inc. (NYSE:CHK) stock increased by 18.3% to $2.10. According to the most recent rating by Raymond James, on August 08, the current rating is at Market Perform.
• QEP Resources, Inc. (NYSE:QEP) shares moved upwards by 17.9% to $4.80. The market value of their outstanding shares is at $2.4 billion. The most recent rating by BMO Capital, on September 10, is at Market Perform, with a price target of $5.00.
• Superior Energy Services, Inc. (NYSE:SPN) shares moved upwards by 17.7% to $0.40. The market cap seems to be at $728.2 million. The most recent rating by Wells Fargo, on September 12, is at Market Perform, with a price target of $1.00.
• Approach Resources, Inc. (NASDAQ:AREX) stock increased by 17.4% to $0.21. The market cap stands at $145.0 million.
• Seadrill, Inc. (NYSE:SDRL) shares rose 16.9% to $3.70. According to the most recent rating by BTIG Research, on August 13, the current rating is at Neutral.
• SM Energy, Inc. (NYSE:SM) stock rose 16.5% to $11.24. The market cap seems to be at $3.3 billion. The most recent rating by KeyBanc, on September 16, is at Overweight, with a price target of $14.00.
• Centennial Resource Dev, Inc. (NASDAQ:CDEV) stock moved upwards by 16.3% to $5.13. The most recent rating by KeyBanc, on September 16, is at Overweight, with a price target of $6.50.
• Laredo Petroleum, Inc. (NYSE:LPI) stock moved upwards by 15.7% to $3.10. The market value of their outstanding shares is at $3.3 billion. According to the most recent rating by JP Morgan, on July 31, the current rating is at Neutral.
• Noble, Inc. (NYSE:NE) shares increased by 15.7% to $2.18. The market value of their outstanding shares is at $3.8 billion.
• ION Geophysical, Inc. (NYSE:IO) shares increased by 15.0% to $10.90. The market value of their outstanding shares is at $388.9 million.
• Roan Resources, Inc. (NYSE:ROAN) shares rose 14.7% to $1.72. The market value of their outstanding shares is at $3.0 billion.
• Oasis Petroleum, Inc. (NYSE:OAS) stock rose 14.2% to $4.25. The market cap stands at $4.2 billion. The most recent rating by Barclays, on August 30, is at Equal-Weight, with a price target of $3.50.
• Diamond Offshore Drilling, Inc. (NYSE:DO) shares moved upwards by 13.8% to $8.75. The most recent rating by Pareto, on September 09, is at Hold, with a price target of $6.30.
• Comstock Resources, Inc. (NYSE:CRK) stock surged 13.8% to $10.84. The market value of their outstanding shares is at $185.9 million.
• Carrizo Oil & Gas, Inc. (NASDAQ:CRZO) shares surged 13.7% to $9.72. According to the most recent rating by KeyBanc, on August 12, the current rating is at Sector Weight.
• Callon Petroleum, Inc. (NYSE:CPE) stock moved upwards by 13.3% to $5.11. The most recent rating by Barclays, on August 30, is at Overweight, with a price target of $6.00.
• Baytex Energy, Inc. (NYSE:BTE) shares surged 13.0% to $1.65. The market cap seems to be at $6.1 billion.
• Continental Resources, Inc. (NYSE:CLR) shares moved upwards by 12.9% to $36.27. The market cap seems to be at $20.8 billion. The most recent rating by Wells Fargo, on August 12, is at Outperform, with a price target of $53.00.
• Transocean, Inc. (NYSE:RIG) stock increased by 12.6% to $6.45. The market value of their outstanding shares is at $16.9 billion. The most recent rating by Citigroup, on August 15, is at Neutral, with a price target of $4.90.
• Nabors Industries, Inc. (NYSE:NBR) shares moved upwards by 12.2% to $2.58. The market cap seems to be at $4.2 billion. According to the most recent rating by Wells Fargo, on September 12, the current rating is at Underperform.
• WPX Energy, Inc. (NYSE:WPX) shares moved upwards by 12.1% to $12.30. The market cap seems to be at $4.1 billion. The most recent rating by Barclays, on August 30, is at Overweight, with a price target of $14.00.
• Murphy Oil, Inc. (NYSE:MUR) shares surged 12.0% to $23.07. The most recent rating by KeyBanc, on September 09, is at Overweight, with a price target of $24.00.
• Southwestern Energy, Inc. (NYSE:SWN) stock surged 11.9% to $2.49. The market cap stands at $14.3 billion. The most recent rating by UBS, on August 14, is at Neutral, with a price target of $1.90.
• Devon Energy, Inc. (NYSE:DVN) shares rose 11.9% to $28.05. According to the most recent rating by SunTrust Robinson Humphrey, on July 30, the current rating is at Buy.
• Marathon Oil, Inc. (NYSE:MRO) shares surged 11.8% to $14.20. The most recent rating by Wells Fargo, on August 12, is at Outperform, with a price target of $20.00.
• Kosmos Energy, Inc. (NYSE:KOS) stock rose 11.5% to $7.00.
• Valaris, Inc. (NYSE:VAL) shares rose 11.2% to $7.05. The market value of their outstanding shares is at $2.5 billion.
• Enerplus, Inc. (NYSE:ERF) shares increased by 10.9% to $8.12. The market cap stands at $3.2 billion.
• Mammoth Energy Services, Inc. (NASDAQ:TUSK) stock rose 10.7% to $3.53. The market cap stands at $699.6 million. According to the most recent rating by Johnson Rice, on September 11, the current rating is at Hold.
• BP Prudhoe Bay, Inc. (NYSE:BPT) stock surged 10.7% to $10.29. The market cap stands at $2.2 billion.
• Parsley Energy, Inc. (NYSE:PE) shares surged 10.6% to $20.45. According to the most recent rating by MKM Partners, on August 27, the current rating is at Buy.
• Crescent Point Energy, Inc. (NYSE:CPG) shares increased by 10.6% to $4.75. The market cap seems to be at $3.7 billion.
• Range Resources, Inc. (NYSE:RRC) stock increased by 10.6% to $5.12. The most recent rating by Ladenburg Thalmann, on August 26, is at Neutral, with a price target of $5.00.
• Matador Resources, Inc. (NYSE:MTDR) shares increased by 10.5% to $18.25. The market value of their outstanding shares is at $669.2 million.
• Vermilion Energy, Inc. (NYSE:VET) shares moved upwards by 10.4% to $18.10. The market value of their outstanding shares is at $4.3 billion.
• Apache, Inc. (NYSE:APA) stock increased by 10.1% to $26.80. The market value of their outstanding shares is at $240.5 million. The most recent rating by Citigroup, on August 26, is at Neutral, with a price target of $22.00.
• Antero Resources, Inc. (NYSE:AR) shares moved upwards by 9.9% to $3.98. The market value of their outstanding shares is at $13.7 billion. According to the most recent rating by Goldman Sachs, on September 06, the current rating is at Neutral.
• Patterson-UTI Energy, Inc. (NASDAQ:PTEN) shares moved upwards by 9.8% to $10.00. The market cap seems to be at $2.0 billion. According to the most recent rating by Wells Fargo, on September 12, the current rating is at Underperform.
• Gulfport Energy, Inc. (NASDAQ:GPOR) shares surged 9.4% to $3.26. The market cap stands at $3.5 billion. The most recent rating by Jefferies, on July 15, is at Hold, with a price target of $5.00.
• Canadian Natural Res, Inc. (NYSE:CNQ) stock moved upwards by 8.9% to $27.60. According to the most recent rating by Wells Fargo, on September 06, the current rating is at Underperform.

Losers

• Energy Transfer, Inc. (NYSE:ET) stock decreased by 0.8% to $13.90 during Monday's pre-market session. The market cap seems to be at $38.7 billion.