This week, these ten stocks have the worst year-to-date performance. Each of these also rates an “F” (“strong sell”) on Portfolio Grader.

Shares of Allied Nevada Gold (ANV) have slipped 56.2% since January 1. Allied Nevada Gold engages in the evaluation, acquisition, exploration, and advancement of gold exploration and development projects. As of Dec. 11, 2014, 35.2% of outstanding Allied Nevada Gold shares were held short. Trade volume is up 722.8% from the previous week. For more information, get Portfolio Grader’s complete analysis of ANV stock.

Since January 1, Coeur Mining, Inc. (CDE) has fallen 58%. Coeur Mining explores, develops, operates, and/or owns silver and gold mining properties and companies. As of Dec. 11, 2014, 14.3% of outstanding Coeur Mining, Inc. shares were held short. Shares of the stock are being traded at a very rapid pace, up 159.4% from the week prior. For more information, get Portfolio Grader’s complete analysis of CDE stock.

Shares of McDermott International, Inc. (MDR) have sunk 60.2% since the first of the year. McDermott International is a worldwide energy services company. As of Dec. 11, 2014, 17.8% of outstanding McDermott International, Inc. shares were held short. Shares of the stock have been changing hands at an unusually rapid pace, up 425% from the week prior. For more information, get Portfolio Grader’s complete analysis of MDR stock.

Since the first of the year, Clean Energy Fuels (CLNE) has dipped 60.8%. Clean Energy Fuels sells natural gas fueling solutions to its customers mainly in the United States and Canada. As of Dec. 11, 2014, 19% of outstanding Clean Energy Fuels shares were held short. Shares of the stock are being traded at a very rapid pace, up 263.2% from the week prior. For more information, get Portfolio Grader’s complete analysis of CLNE stock.

Since the first of the year, Talisman Energy (TLM) has tumbled 66.1%. Talisman Energy is a global diversified upstream oil and gas company. For more information, get Portfolio Grader’s complete analysis of TLM stock.

Shares of Alpha Natural Resources, Inc. (ANR) have slumped 70.3% since the first of the year. Alpha Natural Resources produces, processes and sells steam and metallurgical coal. As of Dec. 11, 2014, 25.1% of outstanding Alpha Natural Resources, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ANR stock.

Shares of Aeropostale, Inc. (ARO) have dipped 70.6% since the first of the year. Aeropostale is a mall-based specialty retailer of casual apparel and accessories. As of Dec. 11, 2014, 26.4% of outstanding Aeropostale, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ARO stock.

Since the first of the year, the price of Resolute Energy Corporation (REN) is down 80%. Resolute Energy explores for and produces oil and natural gas in the southern and western United States. As of Dec. 11, 2014, 11.4% of outstanding Resolute Energy Corporation shares were held short. Trade volume is up 316.2% from the previous week. For more information, get Portfolio Grader’s complete analysis of REN stock.

Shares of Energy XXI Ltd (EXXI) have fallen 87.8% since January 1. Energy XXI explores for and produces oil and natural gas. As of Dec. 11, 2014, 19.2% of outstanding Energy XXI Ltd shares were held short. Shares of the stock have been changing hands at an unusually rapid pace, up 109.4% from the week prior. The stock has a trailing PE Ratio of 106.70. For more information, get Portfolio Grader’s complete analysis of EXXI stock.

Shares of Walter Energy (WLT) have slumped 88.5% since January 1. Walter Energy is a producer and exporter of metallurgical coal for the global steel industry. As of Dec. 11, 2014, 12.2% of outstanding Walter Energy shares were held short. For more information, get Portfolio Grader’s complete analysis of WLT stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.