The overall ratings of four Software stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Taomee Holdings (NYSE:TAOM) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. Taomee Holdings produces children’s entertainment. In Portfolio Grader’s specific subcategories of Earnings Surprise and Margin Growth, TAOM also gets F’s. The stock price has dropped 17.5% over the past month, worse than the 3.1% increase the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of TAOM stock.

This is a rough week for SRS Labs (NASDAQ:SRSL). The company’s rating falls to D from the previous week’s C. SRS Labs develops and licenses audio and voice enhancement technologies. The stock gets F’s in Earnings Growth and Margin Growth. For a full analysis of SRSL stock, visit Portfolio Grader.

TeleNav Inc.’s (NASDAQ:TNAV) rating weakens this week, dropping to a D versus last week’s C. TeleNav provides location-based solutions. The stock gets F’s in Earnings Growth, Earnings Momentum, and Margin Growth. Share prices fell 8.4% over the past month. To get an in-depth look at TNAV, get Portfolio Grader’s complete analysis of TNAV stock.

The rating of Red Hat (NYSE:RHT) slips from C to a D. Red Hat provides open source software solutions that customers are allowed to update, monitor and manage. The stock has a trailing PE Ratio of 68.20. For more information, get Portfolio Grader’s complete analysis of RHT 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.