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

Since the first of the year, the price of EXCO Resources, Inc. (XCO) is down 56.9%. EXCO Resources is an oil and natural gas company involved in the exploration, exploitation, development and production of onshore North American oil and natural gas properties. As of Dec. 18, 2014, 12.3% of outstanding EXCO Resources, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of XCO stock.

The price of Peabody Energy Corporation (BTU) is down 59.3% since the first of the year. Peabody Energy mines steal, coal, and metallurgical coal to sell to electric utilities and industrial customers. As of Dec. 18, 2014, 16.2% of outstanding Peabody Energy Corporation shares were held short. For more information, get Portfolio Grader’s complete analysis of BTU stock.

Since the first of the year, Talisman Energy (TLM) has tumbled 62.6%. Talisman Energy is a global diversified upstream oil and gas company. Shares of the stock have been changing hands at an unusually rapid pace, up 678.6% from the week prior. For more information, get Portfolio Grader’s complete analysis of TLM stock.

Shares of Arch Coal, Inc. (ACI) have dipped 62.8% since the first of the year. Arch Coal produces coal and sells it to power plants, steel mills, and industrial facilities. As of Dec. 18, 2014, 21.7% of outstanding Arch Coal, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ACI stock.

Since the first of the year, Clean Energy Fuels (CLNE) has dipped 64.6%. Clean Energy Fuels sells natural gas fueling solutions to its customers mainly in the United States and Canada. As of Dec. 18, 2014, 18.1% of outstanding Clean Energy Fuels shares were held short. For more information, get Portfolio Grader’s complete analysis of CLNE stock.

Share prices of McDermott International, Inc. (MDR) are down 69.9% since the first of the year. McDermott International is a worldwide energy services company. As of Dec. 18, 2014, 16.1% of outstanding McDermott International, Inc. shares were held short. Shares of the stock are being traded at a very rapid pace, up 159% from the week prior. For more information, get Portfolio Grader’s complete analysis of MDR stock.

Shares of Aeropostale, Inc. (ARO) have sunk 72.9% since the first of the year. Aeropostale is a mall-based specialty retailer of casual apparel and accessories. As of Dec. 18, 2014, 24.5% of outstanding Aeropostale, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ARO stock.

Shares of Alpha Natural Resources, Inc. (ANR) have slipped 76.6% since January 1. Alpha Natural Resources produces, processes and sells steam and metallurgical coal. As of Dec. 18, 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 Walter Energy (WLT) have slumped 87.8% since January 1. Walter Energy is a producer and exporter of metallurgical coal for the global steel industry. As of Dec. 18, 2014, 12.2% of outstanding Walter Energy shares were held short. For more information, get Portfolio Grader’s complete analysis of WLT stock.

Since the first of the year, Energy XXI Ltd (EXXI) has dipped 89.6%. Energy XXI explores for and produces oil and natural gas. As of Dec. 18, 2014, 19.4% of outstanding Energy XXI Ltd shares were held short. The stock has a trailing PE Ratio of 86.70. For more information, get Portfolio Grader’s complete analysis of EXXI 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.