This week, four chemicals stocks are improving their overall rating on Portfolio Grader. Each of these rates 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. For more information, get Portfolio Grader’s complete analysis of PAH stock.

Valspar Corporation (VAL) shows solid improvement this week. The company’s rating rises from a C to a B. 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 progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. For more information, get Portfolio Grader’s complete analysis of FNRG stock.

Potash Corporation of Saskatchewan Inc.’s (POT) ratings are looking better this week, moving up to a B from last week’s C. Potash Corporation of Saskatchewan produces potash, phosphate, and nitrogen to the agricultural and industrial industries worldwide. 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.