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 January 1, 3D Systems Corporation (DDD) has plunged 57.1%. 3D Systems engages in the design, development, manufacture, marketing, and servicing of 3D printers and related products, print materials, and services. As of Aug. 20, 2015, 31% of outstanding 3D Systems Corporation shares were held short. For more information, get Portfolio Grader’s complete analysis of DDD stock.

Since the first of the year, Freeport-McMoRan, Inc. (FCX) has dipped 57.3%. Freeport-McMoRan Copper & Gold is a copper, gold, and molybdenum mining company. For more information, get Portfolio Grader’s complete analysis of FCX stock.

For more information, get Portfolio Grader’s complete analysis of CSTM stock.

Shares of Empresas ICA SAB de CV Sponsored ADR (ICA) have slumped 59.2% since the first of the year. Empresas ICA S.A.B. de C.V. offers engineering and construction services. For more information, get Portfolio Grader’s complete analysis of ICA stock.

Since the first of the year, the price of Helix Energy Solutions Group, Inc. (HLX) is down 66.8%. Helix Energy Solutions is a marine contractor and operator of offshore oil and gas properties and production facilities. For more information, get Portfolio Grader’s complete analysis of HLX stock.

Shares of Ocwen Financial Corporation (OCN) have slipped 67.1% since January 1. Ocwen Financial is a diversified financial services holding company. As of Aug. 20, 2015, 22.1% of outstanding Ocwen Financial Corporation shares were held short. For more information, get Portfolio Grader’s complete analysis of OCN stock.

Shares of Stone Energy Corporation (SGY) have slumped 71.7% since January 1. Stone Energy is an independent oil and natural gas company engaged in the acquisition, exploration, exploitation, development and operation of oil and gas properties. As of Aug. 20, 2015, 15.7% of outstanding Stone Energy Corporation shares were held short. For more information, get Portfolio Grader’s complete analysis of SGY stock.

Shares of Natural Resource Partners (NRP) have dipped 72% since the first of the year. Natural Resource Partners owns and manages coal properties in Appalachia, the Illinois Basin, and the Western United States. For more information, get Portfolio Grader’s complete analysis of NRP stock.

Since the first of the year, Magnum Hunter Resources Corporation (MHR) has dipped 72.2%. Magnum Hunter Resources explores for oil and natural gas. As of Aug. 20, 2015, 27.1% of outstanding Magnum Hunter Resources Corporation shares were held short. For more information, get Portfolio Grader’s complete analysis of MHR stock.

Shares of Peabody Energy Corporation (BTU) have sunk 87.2% since the first of the year. Peabody Energy mines steal, coal, and metallurgical coal to sell to electric utilities and industrial customers. As of Aug. 20, 2015, 36.5% of outstanding Peabody Energy Corporation shares were held short. Shares of the stock have been changing hands at an unusually rapid pace, up 146.5% from the week prior. For more information, get Portfolio Grader’s complete analysis of BTU 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.