This week, four chemicals stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

Platform Specialty Products Corp. (PAH) is making progress this week as its rating of C (“hold”) from last week increases to a B (“buy”) rating this week. In Portfolio Grader’s specific subcategory of Earnings Surprise, PAH also gets an A. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of PAH stock.

Valspar Corporation (VAL) is seeing ratings go up from a C last week to a B this week. Valspar is a coating and paint manufacturer and distributor. For more information, get Portfolio Grader’s complete analysis of VAL stock.

ForceField Energy Inc. (FNRG) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. Shares of the stock have been trading at an exceptionally rapid pace, up twofold from the week prior. For more information, get Portfolio Grader’s complete analysis of FNRG stock.

This week, Potash Corporation of Saskatchewan Inc. (POT) pushes up from a C to a B rating. Potash Corporation of Saskatchewan produces potash, phosphate, and nitrogen to the agricultural and industrial industries worldwide. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of POT 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.