For the current week, the overall ratings of five Internet and Web Service stocks are worse, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Zix Corp. (NASDAQ:ZIXI) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. Zix provides secure, Internet-based applications in a Software-as-a-Service (SaaS) model. For Portfolio Grader’s specific subcategory of Margin Growth, ZIXI also gets an F. For a full analysis of ZIXI stock, visit Portfolio Grader.

SINA Corp.’s (NASDAQ:SINA) rating weakens this week, dropping to a D versus last week’s C. 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 has a trailing PE Ratio of 99.30. To get an in-depth look at SINA, get Portfolio Grader’s complete analysis of SINA stock.

Dice Holdings (NYSE:DHX) experiences a ratings drop this week, going from last week’s C to a D. Dice Holdings provides specialized career Websites and career fairs for professional communities. For more information, get Portfolio Grader’s complete analysis of DHX stock.

This is a rough week for IAC/InterActiveCorp. (NASDAQ:IACI). The company’s rating falls to D from the previous week’s C. IAC is an Internet company that reports revenue in search, personals, media & other areas. The stock also rates an F in Earnings Momentum. The stock price has fallen 12.2% over the past month, worse than the 3.9% increase the Nasdaq has seen over the same period of time. For a full analysis of IACI stock, visit Portfolio Grader.

LogMeIn Inc. (NASDAQ:LOGM) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). LogMeIn offers remote connectivity services to computers for mobile professionals, and help desk and systems administrators worldwide. The stock also gets an F in Margin Growth. As of Jan. 25, 2013, 12.4% of outstanding LogMeIn Inc. shares were held short. The stock currently has a trailing PE Ratio of 179.50. To get an in-depth look at LOGM, get Portfolio Grader’s complete analysis of LOGM 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.