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

This week, ARRIS Group, Inc. (ARRS) falls to a D (“sell”), worse than last week’s grade of C (“hold”). ARRIS is a global communications technology company specializing in the design and engineering of broadband network solutions. As of July 9, 2015, 11.7% of outstanding ARRIS Group, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of ARRS stock.

Applied Optoelectronics, Inc.’s (AAOI) rating falls this week to an F (“strong sell”), down from last week’s C (“sell”). The stock gets F’s in Earnings Surprise and Cash Flow. As of July 9, 2015, 13.9% of outstanding Applied Optoelectronics, Inc. shares were held short. The stock currently has a trailing PE Ratio of 77.50. To get an in-depth look at AAOI, get Portfolio Grader’s complete analysis of AAOI stock.

This week, Dragonwave Inc.’s (DRWI) rating worsens to a D from the company’s C rating a week ago. DragonWave is a producer of high-capacity packet microwave solutions which support networking and other data transmission needs. The stock gets F’s in Equity and Cash Flow. For more information, get Portfolio Grader’s complete analysis of DRWI stock.

The rating of Clearfield, Inc. (CLFD) slips from a D to an F. Clearfield offers telecommunications equipment and products in the United States. The stock gets F’s in Earnings Growth, Earnings Momentum and Sales Growth. As of July 9, 2015, 12.1% of outstanding Clearfield, Inc. shares were held short. Shares of the stock are changing hands at twice the rate they were a week ago. The trailing PE Ratio for the stock is 61.90. To get an in-depth look at CLFD, get Portfolio Grader’s complete analysis of CLFD stock.

This is a rough week for Sonus Networks, Inc. (SONS). The company’s rating falls to D from the previous week’s C. Sonus Networks provides voice infrastructure solutions for wireline and wireless service providers. For more information, get Portfolio Grader’s complete analysis of SONS 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.