The overall ratings of three Chemicals stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

China Green Agriculture (NYSE:CGA) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. China Green Agriculture engages in the research, development, production, and sale of various types of fertilizers and agricultural products in the People’s Republic of China. For more information, get Portfolio Grader’s complete analysis of CGA stock.

Olin Corp. (NYSE:OLN) earns a D this week, moving down from last week’s grade of C. Olin Corporation manufactures and sells chlorine, caustic soda, sodium hydrosulfite, hydrochloric acid, hydrogen, sodium chlorate, bleach products, and potassium hydroxide. To get an in-depth look at OLN, get Portfolio Grader’s complete analysis of OLN stock.

The rating of Innophos Holdings (NASDAQ:IPHS) slips from C to a D. Innophos Holdings produces phosphate salts, acids, and related products. The stock price has dropped 5.6% over the past month, worse than the 4.2% increase the Nasdaq has seen over the same period of time. For a full analysis of IPHS stock, visit Portfolio Grader.

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.