The ratings of four internet and web service stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Reis, Inc. (REIS) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. Reis is engaged in the business of providing commercial real estate market information and analytical tools for its customers. In Portfolio Grader’s specific subcategories of Earnings Momentum and Earnings Surprise, REIS also gets F’s. To get an in-depth look at REIS, get Portfolio Grader’s complete analysis of REIS stock.

Wix.com Ltd. (WIX) gets weaker ratings this week as last week’s C drops to a D. The stock also rates an F in Equity. For more information, get Portfolio Grader’s complete analysis of WIX stock.

iPass’ (IPAS) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). 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 receives F’s in Earnings Revisions, Equity, Cash Flow and Sales Growth. To get an in-depth look at IPAS, get Portfolio Grader’s complete analysis of IPAS stock.

The rating of Velti (VELT) slips from a D to an F. 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.

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.