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 Diamond Offshore Drilling, Inc. (DO) have fallen 15.8% since January 1. Diamond Offshore Drilling is a global offshore oil and gas drilling contractor. For more information, get Portfolio Grader’s complete analysis of DO stock.

Shares of First BanCorp (FBP) have dipped 17.2% since the first of the year. First BanCorp is the holding company for FirstBank Puerto Rico. For more information, get Portfolio Grader’s complete analysis of FBP stock.

Since the first of the year, Atlas Air Worldwide Holdings, Inc. (AAWW) has tumbled 17.5%. Atlas Air Worldwide is engaged in leasing and outsourcing services for wide-body freighter aircraft. As of Feb. 20, 2014, 11.2% of outstanding Atlas Air Worldwide Holdings, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of AAWW stock.

Since January 1, Elizabeth Arden, Inc. (RDEN) has fallen 20.2%. Elizabeth Arden manufactures, distributes, and markets prestige fragrances and related skin treatment and cosmetic products for men and women. The stock’s trailing PE Ratio is 28.30. For more information, get Portfolio Grader’s complete analysis of RDEN stock.

Since the first of the year, the price of Cencosud S.A. Sponsored ADR (CNCO) is down 20.2%. Cencosud operates as a multi-brand retailer in Argentina, Brazil, Chile, Peru, and Colombia. The stock has a trailing PE Ratio of 56.80. For more information, get Portfolio Grader’s complete analysis of CNCO stock.

Shares of Alpha Natural Resources, Inc. (ANR) have slipped 20.3% since January 1. Alpha Natural Resources produces, processes and sells steam and metallurgical coal. As of Feb. 20, 2014, 24.6% of outstanding Alpha Natural Resources, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ANR stock.

Since the first of the year, Clean Energy Fuels (CLNE) has dipped 24.6%. Clean Energy Fuels sells natural gas fueling solutions to its customers mainly in the United States and Canada. As of Feb. 20, 2014, 20.9% of outstanding Clean Energy Fuels shares were held short. For more information, get Portfolio Grader’s complete analysis of CLNE stock.

The price of RentACenter, Inc. (RCII) has fallen 25.4% since the first of the year. Rent-A-Center operates in the rent-to-own industry in the United States. As of Feb. 20, 2014, 15% of outstanding RentACenter, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of RCII stock.

Since January 1, J. C. Penney Company, Inc. (JCP) has plunged 26.5%. J. C. Penney operates department stores in the United States and Puerto Rico. As of Feb. 20, 2014, 38.9% of outstanding J. C. Penney Company, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of JCP stock.

Shares of Weight Watchers International, Inc. (WTW) have sunk 31.2% since the first of the year. Weight Watchers is a provider of weight management services, operating globally through a network of company-owned and franchise operations. As of Feb. 20, 2014, 22.8% of outstanding Weight Watchers International, Inc. shares were held short. Shares of the stock have been changing hands at an unusually rapid pace, up 225% from the week prior. For more information, get Portfolio Grader’s complete analysis of WTW 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.