The ratings of four Software stocks are down this week, according to the Portfolio Grader database. 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. For a full analysis of TAOM stock, visit Portfolio Grader.

SRS Labs’ (NASDAQ:SRSL) rating weakens this week, dropping to a D versus last week’s C. SRS Labs develops and licenses audio and voice enhancement technologies. The stock gets F’s in Earnings Growth and Margin Growth. To get an in-depth look at SRSL, get Portfolio Grader’s complete analysis of SRSL stock.

Slipping from C to a D rating, TeleNav Inc. (NASDAQ:TNAV) takes a hit this week. TeleNav provides location-based solutions. The stock gets F’s in Earnings Growth, Earnings Momentum, and Margin Growth. The stock price has fallen 9.9% over the past month, worse than the Nasdaq, which has held flat over the same period of time. For more information, get Portfolio Grader’s complete analysis of TNAV stock.

Red Hat (NYSE:RHT) earns a D this week, moving down from last week’s grade of C. Red Hat provides open source software solutions that customers are allowed to update, monitor and manage. Share prices fell 9.4% over the past month. The stock’s trailing PE Ratio is 72.90. For a full analysis of RHT 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.