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 beginning of the year, the Nasdaq rose 10.9%, the Dow is up 13.2%, and the S&P is up 12.1%.

Shares of Endeavour Silver (NYSE:EXK) have dipped 48.7% since the first of the year. Endeavor Silver is a small-cap silver mining company focused on the growth of its silver production, reserves and resources in Mexico. For more information, get Portfolio Grader’s complete analysis of EXK stock.

Shares of Molycorp, Inc. (NYSE:MCP) have slipped 49.5% since January 1. Molycorp produces rare earth products, including oxides, metals, alloys and magnets for a variety of applications including clean energy technologies, technology, and defense applications. As of Nov. 7, 2013, 20.6% of outstanding Molycorp, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of MCP stock.

Since the first of the year, the price of Walter Energy (NYSE:WLT) is down 49.7%. Walter Energy is a producer and exporter of metallurgical coal for the global steel industry. As of Nov. 7, 2013, 13.3% of outstanding Walter Energy shares were held short. For more information, get Portfolio Grader’s complete analysis of WLT stock.

Shares of Mechel OAO Sponsored ADR (NYSE:MTL) have slumped 53% since January 1. Mechel is a Russian metals and mining company, uniting producers of steel, rolled products, hardware, coal, iron ore concentrate, and nickel. For more information, get Portfolio Grader’s complete analysis of MTL stock.

Shares of NovaGold Resources (AMEX:NG) have fallen 53.3% since January 1. NovaGold Resources explores and develops mineral properties in North America. For more information, get Portfolio Grader’s complete analysis of NG stock.

Share prices of NII Holdings, Inc. Class B (NASDAQ:NIHD) are down 54.1% since the first of the year. NII Holdings provides mobile communications for business customers in Latin America. As of Nov. 7, 2013, 34.6% of outstanding NII Holdings, Inc. Class B shares were held short. For more information, get Portfolio Grader’s complete analysis of NIHD stock.

Since the first of the year, IAMGOLD Corporation (NYSE:IAG) has dipped 55.4%. Iamgold is involved in the exploration for, and development and production of mineral resource properties throughout the world. For more information, get Portfolio Grader’s complete analysis of IAG stock.

Since the first of the year, J. C. Penney Company, Inc. (NYSE:JCP) has tumbled 58.7%. J. C. Penney operates department stores in the United States and Puerto Rico. As of Nov. 7, 2013, 25.2% of outstanding J. C. Penney Company, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of JCP stock.

Since January 1, Harmony Gold Mining Co. Ltd. Sponsored ADR (NYSE:HMY) has plunged 60.2%. Harmony Gold Mining is a mining company which produces gold from its operations in the district of Virginia, Orange Free State. For more information, get Portfolio Grader’s complete analysis of HMY stock.

Since January 1, Gold Fields Limited Sponsored ADR (NYSE:GFI) has fallen 63%. Gold Fields is engaged in the mining, exploration, extraction, processing, and smelting of gold. For more information, get Portfolio Grader’s complete analysis of GFI 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.