NEW YORK ( TheStreet) -- Trina Solar (TSL - Get Report), Renesola (SOL), Tesoro Corp (TSO - Get Report), Yingli Green Energy Holding (YGE), Oceaneering International (OII - Get Report) and China Petroleum & Chemical Corp (SNP - Get Report) gained last week, whereas Frontline Ltd/Bermuda (FRO), Quicksilver Resources (KWK), Comstock Resources (CRK - Get Report), First Oil (FST) and Teekay Offshore Partners (TOO) eroded substantial value.
Trina Solar led the pack of winners, up 20.1%. Ahmar Zaman, analyst at Piper Jaffray, has raised the stock to overweight from neutral with a 12-month target price of $19 per share.
ReneSola jumped 16.4% after it announced to repurchase up to $100 million in aggregate value of the company's outstanding ordinary shares.
Yingli Green Energy Holding
rallied 16.3% on an upgrade to neutral from underweight from analysts at HSBC. Piper Jaffray has raised the stock's rating to overweight from neutral, and Avian Securities has upped its rating to positive from negative.
Tesoro Corp gained 15.8% after Mark Gilman, an equity analyst at Benchmark, raised the stock to buy from sell. The stock has a 12-month target price of $25 per share.
moved up 15.4%, ahead of its second-quarter earnings release on August 29. The company recently lowered its guidance estimate for the second quarter, and fiscal 2011.
rose 13.9% after analysts at Dahlman Rose increased the stock's price target to $229 per share from $216, maintaining a buy rating on it. The company intends to build a $100 million plant in Jenkins County, pending environmental permits that are expected in October, The Millen News reports.
gained 13.6% after analysts at Collins Stewart upgraded the stock to buy from neutral with a price target of $132 per share.
(OII - Get Report)
increased 13% during this past week.
Other movers last week included Complete Production Services
Helix Energy Solutions Group
Helmerich & Payne
Precision Drilling Corp
Cabot Oil & Gas
China Petroleum & Chemical Corp
(SNP - Get Report)
increased 8% for the week.
Key Energy Services
moved up 7.9%,
rose 7.5% and
closed 7.3% higher.
rose 7.2% this past week. The company has announced plans to supply gasoline and diesel to Libya in the next few days. ENI's chief executive Paolo Scaroni said the company will increase natural gas production at the earliest, while resumption of oil output would take another 6 to 18 months, Bloomberg reports.