This week, the ratings of 11 internet and web service stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Youku Tudou, Inc. Sponsored ADR Class A (YOKU) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Youku Tudou is an Internet television company. Trade volume is up 913.7% from the previous week. For more information, get Portfolio Grader’s complete analysis of YOKU stock.

Marchex, Inc. Class B (MCHX) experiences a ratings drop this week, going from last week’s D to an F. Marchex offers call-based advertising and related services, pay-per-click advertising and related services and proprietary traffic sources. The stock receives F’s in Earnings Growth, Earnings Momentum and Earnings Surprise. Equity and Cash Flow also get F’s. Shares of the stock are being traded at a very rapid pace, up 1711.2% from the week prior. To get an in-depth look at MCHX, get Portfolio Grader’s complete analysis of MCHX stock.

This week, Unwired Planet, Inc. (UPIP) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Unwired Planet develops patents that allow mobile devices to connect to the Internet. The stock gets F’s in Earnings Revisions and Equity. Trade volume is up 1086.3% from the previous week. For more information, get Portfolio Grader’s complete analysis of UPIP stock.

This week, ChinaCache International Holdings Ltd. Sponsored ADR (CCIH) drops from a C to a D rating. 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. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. To get an in-depth look at CCIH, get Portfolio Grader’s complete analysis of CCIH stock.

E2open, Inc.’s (EOPN) rating weakens this week, dropping to an F versus last week’s D. E2open develops and deploys enterprise software cloud solutions for businesses. The stock gets F’s in Equity and Cash Flow. Shares of the stock are being traded at a very rapid pace, up 695.3% from the week prior. For more information, get Portfolio Grader’s complete analysis of EOPN stock.

iPass (IPAS) is having a tough week. The company’s rating falls from a D to an F. iPass offers enterprise mobility services on a global basis by providing services that simply, smartly and openly facilitate network access from mobile devices while providing the enterprise with visibility and control over their mobile ecosystem. The stock gets F’s in Earnings Revisions, Equity, Cash Flow and Sales Growth. Shares of the stock have been changing hands at an unusually rapid pace, up 6303.1% from the week prior. To get an in-depth look at IPAS, get Portfolio Grader’s complete analysis of IPAS stock.

This week, Velti’s (VELT) rating worsens to an F from the company’s D rating a week ago. Velti is a global provider of mobile marketing and advertising solutions. The stock gets F’s in Earnings Growth and Earnings Momentum. For more information, get Portfolio Grader’s complete analysis of VELT stock.

Travelzoo (TZOO) gets weaker ratings this week as last week’s D drops to an F. Travelzoo is an Internet media company that publishes travel and entertainment deals from travel and entertainment companies, and local businesses in North America, Europe, and the Asia Pacific. The stock gets F’s in Earnings Growth, Earnings Revisions and Sales Growth. Trade volume is up 384.7% from the previous week. To get an in-depth look at TZOO, get Portfolio Grader’s complete analysis of TZOO stock.

The rating of Zix Corporation (ZIXI) declines this week from a C to a D. Zix provides secure, Internet-based applications in a Software-as-a-Service (SaaS) model. The stock gets F’s in Earnings Growth, Earnings Momentum and Earnings Surprise. The stock has a trailing PE Ratio of 57.00. For more information, get Portfolio Grader’s complete analysis of ZIXI stock.

This week, Homeaway, Inc.’s (AWAY) rating worsens to an F from the company’s D rating a week ago. HomeAway operates an online marketplace for the vacation rental industry worldwide, and offers homes, condominiums, villas, and cabins to the public on a nightly, weekly, or monthly basis. The stock gets F’s in Earnings Growth and Margin Growth. Trade volume is up 449% from the previous week. The stock’s trailing PE Ratio is 223.50. To get an in-depth look at AWAY, get Portfolio Grader’s complete analysis of AWAY stock.

This is a rough week for CoStar Group, Inc. (CSGP). The company’s rating falls to D from the previous week’s C. CoStar provides information and analytic services to the commercial real estate industry in the United States, the United Kingdom, and France. The stock also rates an F in Earnings Momentum. Shares of the stock have been changing hands at an unusually rapid pace, up 661% from the week prior. The stock currently has a trailing PE Ratio of 129.60. For more information, get Portfolio Grader’s complete analysis of CSGP 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.