The grades of four pharmaceutical stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

This week, NuPathe Inc. (PATH) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). NuPathe develops pharmaceutical products used for the treatment and management of neurological and psychiatric diseases. In Portfolio Grader’s specific subcategories of Earnings Momentum and Earnings Revisions, PATH also gets A’s. For more information, get Portfolio Grader’s complete analysis of PATH stock.

Watson Pharmaceuticals (WPI) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. Watson develops, manufactures, markets, sells and distributes pharmaceutical products. For more information, get Portfolio Grader’s complete analysis of WPI stock.

Impax Laboratories, Inc. (IPXL) shows solid improvement this week. The company’s rating rises from a C to a B. Impax Laboratories develops, manufactures, and markets both proprietary and multi-source pharmaceutical products utilizing its drug delivery technologies. Shares of the stock have been changing hands at an unusually rapid pace, up 822.2% from the week prior. For more information, get Portfolio Grader’s complete analysis of IPXL stock.

Mylan (MYL) boosts its rating from a B to an A this week. Mylan is a global generic and specialty pharmaceuticals company. For more information, get Portfolio Grader’s complete analysis of MYL 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.