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

ARRIS Group, Inc.’s (ARRS) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. ARRIS is a global communications technology company specializing in the design and engineering of broadband network solutions. As of June 11, 2015, 10.6% of outstanding ARRIS Group, Inc. shares were held short. To get an in-depth look at ARRS, get Portfolio Grader’s complete analysis of ARRS stock.

Applied Optoelectronics, Inc. (AAOI) earns an F (“strong sell”) this week, moving down from last week’s grade of C (“sell”). The stock gets F’s in Earnings Surprise and Cash Flow. As of June 11, 2015, 13% of outstanding Applied Optoelectronics, Inc. shares were held short. The stock has a trailing PE Ratio of 79.70. For more information, get Portfolio Grader’s complete analysis of AAOI stock.

This week, Dragonwave Inc. (DRWI) drops from a C to a D rating. 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. To get an in-depth look at DRWI, get Portfolio Grader’s complete analysis of DRWI stock.

Clearfield, Inc. (CLFD) gets weaker ratings this week as last week’s D drops 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 June 11, 2015, 11.7% of outstanding Clearfield, Inc. shares were held short. The stock currently has a trailing PE Ratio of 60.70. For more information, get Portfolio Grader’s complete analysis of CLFD stock.

Sonus Networks, Inc. (SONS) experiences a ratings drop this week, going from last week’s C to a D. Sonus Networks provides voice infrastructure solutions for wireline and wireless service providers. To get an in-depth look at SONS, 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.