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

Boingo Wireless‘s (NASDAQ:WIFI) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. Boingo Wireless installs, manages, and operates wireless network infrastructure to provide Wi-Fi services at its managed and operated hotspots. In Portfolio Grader’s specific subcategories of Earnings Surprise and Margin Growth, WIFI also gets F’s. The stock price has dropped 37.7% over the past month, worse than the 4.6% increase the Nasdaq has seen over the same period of time. The trailing PE Ratio for the stock is 45. For a full analysis of WIFI stock, visit Portfolio Grader.

This week, Leap Wireless (NASDAQ:LEAP) drops from a C to a D rating. Leap Wireless provides mobile wireless services. The stock gets F’s in Earnings Momentum, Equity, and Cash Flow. As of Aug. 16, 18.4% of outstanding Leap Wireless shares were held short. Shares of the company are down 5.1% from a month ago. 

To get an in-depth look at LEAP, get Portfolio Grader’s complete analysis of LEAP stock.

NTT DoCoMo Inc. ADS‘s (NYSE:DCM) rating weakens this week, dropping to a D versus last week’s C. NTT DoCoMo is a wireless telecommunications services provider that offers wireless voice and data communication services on networks that are accessible by the entire population in Japan. The stock also gets an F in Sales Growth. DCM shares have remained flat over the past month. For a full analysis of DCM stock, visit Portfolio Grader.

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.