This week, the overall grades of three Internet and Web Service stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Limelight Network‘s (NASDAQ:LLNW) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. Limelight Networks is a content delivery network for internet distribution of video, music, games and downloads. In Portfolio Grader’s specific subcategories of Earnings Revisions and Equity, LLNW also gets F’s. The stock price has dropped 6.8% over the past month, worse than the 4.9% increase the Nasdaq has seen over the same period of time. For a full analysis of LLNW stock, visit Portfolio Grader.

ChinaCache International Holdings (NASDAQ:CCIH) earns a D this week, moving down from last week’s grade of C. ChinaCache International provides a portfolio of services and solutions to businesses, government agencies and other enterprises to enhance the reliability and scalability of their online services and applications and improve end-user experience. The stock price has fallen 6% over the past month. The stock’s trailing PE Ratio is 65.8. For more information, get Portfolio Grader’s complete analysis of CCIH stock.

SINA Corp. (NASDAQ:SINA) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a D (“sell”). SINA is an online media company and mobile value-added information services provider in the People’s Republic of China and in Chinese communities around the world. The stock gets F’s in Earnings Revisions, Earnings Surprise, and Cash Flow. For a full analysis of SINA 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.