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 American Eagle Outfitters, Inc. (AEO) have slipped 27.8% since January 1. American Eagle Outfitters designs, markets, and sells its own brand of low-price clothing, accessories, and personal care products for young adults. As of July 31, 2014, 17.2% of outstanding American Eagle Outfitters, Inc. shares were held short. The stock’s trailing PE Ratio is 34.30. For more information, get Portfolio Grader’s complete analysis of AEO stock.

Since the first of the year, RentACenter, Inc. (RCII) has tumbled 28.1%. Rent-A-Center operates in the rent-to-own industry in the United States. As of July 31, 2014, 15.3% of outstanding RentACenter, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of RCII stock.

Since the first of the year, Arch Coal, Inc. (ACI) has dipped 32.6%. Arch Coal produces coal and sells it to power plants, steel mills, and industrial facilities. As of July 31, 2014, 18% of outstanding Arch Coal, Inc. shares were held short. Shares of the stock have been changing hands at an unusually rapid pace, up 102% from the week prior. For more information, get Portfolio Grader’s complete analysis of ACI stock.

Since January 1, CGG Sponsored ADR (CGG) has plunged 34.5%. CGG provides geophysical services and software products and manufactures geophysical equipment. For more information, get Portfolio Grader’s complete analysis of CGG stock.

Shares of Weight Watchers International, Inc. (WTW) have fallen 37.1% since January 1. Weight Watchers is a provider of weight management services, operating globally through a network of company-owned and franchise operations. As of July 31, 2014, 21.5% of outstanding Weight Watchers International, Inc. shares were held short. Trade volume is up 222.5% from the previous week. For more information, get Portfolio Grader’s complete analysis of WTW stock.

Since January 1, Elizabeth Arden, Inc. (RDEN) has fallen 40.6%. Elizabeth Arden manufactures, distributes, and markets prestige fragrances and related skin treatment and cosmetic products for men and women. The stock has a trailing PE Ratio of 129.90. For more information, get Portfolio Grader’s complete analysis of RDEN stock.

Since January 1, UTi Worldwide (UTIW) has plunged 41.9%. UTi Worldwide is a supply chain services and solutions company. As of July 31, 2014, 10.4% of outstanding UTi Worldwide shares were held short. Shares of the stock have been changing hands at an unusually rapid pace, up 180.7% from the week prior. For more information, get Portfolio Grader’s complete analysis of UTIW stock.

Shares of Alpha Natural Resources, Inc. (ANR) have fallen 48.4% since January 1. Alpha Natural Resources produces, processes and sells steam and metallurgical coal. As of July 31, 2014, 24.1% of outstanding Alpha Natural Resources, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ANR stock.

The price of Walter Energy (WLT) is down 60.1% since the first of the year. Walter Energy is a producer and exporter of metallurgical coal for the global steel industry. As of July 31, 2014, 12.6% of outstanding Walter Energy shares were held short. For more information, get Portfolio Grader’s complete analysis of WLT stock.

Share prices of Aeropostale, Inc. (ARO) are down 62.4% since the first of the year. Aeropostale is a mall-based specialty retailer of casual apparel and accessories. As of July 31, 2014, 30.9% of outstanding Aeropostale, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ARO 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.