This week, the overall grades of four 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”).

RealNetworks‘s (NASDAQ:RNWK) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. RealNetworks develops and markets software products and services. In Portfolio Grader’s specific subcategories of Equity, Cash Flow, and Sales Growth, RNWK also gets an F. The price of RNWK declined 0.7% from a month ago. This is worse than the 5.7% increase seen by the Nasdaq for the same period. 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 RNWK, get Portfolio Grader’s complete analysis of RNWK stock.

Responsys (NASDAQ:MKTG) experiences a ratings drop this week, going from last week’s C to a D. Responsys provides solutions to businesses in the retail, travel and hospitality, financial services, and high-technology sectors. The stock also gets an F in Earnings Momentum. The stock price has dropped 13.6% over the past month. The trailing PE Ratio for the stock is 58.9. For more information, get Portfolio Grader’s complete analysis of MKTG stock.

Qihoo 360 Technology (NYSE:QIHU) is having a tough week. The company’s rating falls from a C to a D rating. Qihoo 360 Technology provides Internet and mobile security products in the People’s Republic of China. As of Aug. 17, 14.6% of outstanding Qihoo 360 Technology shares were held short. Shares of the stock have been trading at an exceptionally rapid pace, up threefold from the week prior. The stock’s trailing PE Ratio is 124.5. To get an in-depth look at QIHU, get Portfolio Grader’s complete analysis of QIHU stock.

KIT digital‘s (NASDAQ:KITD) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”) last week. KIT Digital is a global provider of on-demand, Internet-Protocol-based video asset management solutions. The stock gets F’s in Earnings Revisions, Equity, and Cash Flow. Investors seem to agree with the downgrade and have pushed down the share price 30.5% over the past month. As of Aug. 17, 27.1% of outstanding KIT digital shares were held short. For a full analysis of KITD 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.