The grades of three medical devices 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, Winner Medical Group (WWIN) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. Winner Medical Group engages in the research, development, manufacture, and marketing of cotton-base medical dressings and medical disposables. For more information, get Portfolio Grader’s complete analysis of WWIN stock.

Globus Medical, Inc. Class A (GMED) gets a higher grade this week, advancing from a B last week to an A. Globus Medical focuses on the design, development, and commercialization of products that promote healing in patients with spine disorders. Shares of the stock have been changing hands at an unusually rapid pace, three times the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of GMED stock.

Atrion Corporation’s (ATRI) ratings are looking better this week, moving up to an A from last week’s B. Atrion engages in the design, development, manufacture, sale, and distribution of products mainly for the medical and healthcare industries. The current dividend yield is 2.6%. For more information, get Portfolio Grader’s complete analysis of ATRI 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.