This week, the ratings of 3 Metals & Mining stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Southern Copper Corporation (SCCO) drops from a C to a D rating. Southern Copper Corporation is an integrated copper producer. The company also gets F’s in sales growth, earnings revisions, and earnings surprise. For more information, get Portfolio Grader’s complete analysis of SCCO stock.

This week, Aluminum Corporation of China Limited Sponsored ADR Class H’s (ACH) rating worsens to a F from the company’s D rating a week ago. Aluminum Corporation of China Limited Sponsored ADR Class H is a producer of aluminium, with operations in bauxite mining, alumina refining, primary aluminium smelting, and aluminium fabrication. The company also gets F’s in sales growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ACH stock.

Slipping from a C to a D rating, Turquoise Hill Resources Ltd. (TRQ) takes a hit this week. Turquoise Hill Resources Ltd. explores for and develops mineral and metal properties in Asia and Australia. The company also gets F’s in sales growth and earnings revisions. For more information, get Portfolio Grader’s complete analysis of TRQ 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.