This week, these five stocks have the worst ratings in Sales Growth, one of the eight Fundamental Categories on Portfolio Grader.

Achillion (NASDAQ:ACHN) focuses on the discovery, development and commercialization of innovative treatments for infectious diseases. ACHN also gets an F in Equity. For more information, get Portfolio Grader’s complete analysis of ACHN stock.

Navidea Biopharmaceuticals (AMEX:NAVB) is focused on the development and commercialization of precision radiopharmaceutical diagnostics for diseases such as cancer. NAVB gets F’s in Analyst Earnings Revisions, Equity, and Cash Flow as well. For more information, get Portfolio Grader’s complete analysis of NAVB stock.

Unwired Planet (NASDAQ:UPIP) provides open Internet-based communication infrastructure software and applications. UPIP also gets F’s in Earnings Growth, Analyst Earnings Revisions, Equity, Cash Flow, and Operating Margin Growth. For more information, get Portfolio Grader’s complete analysis of UPIP stock.

City Telecom (H.K.) Ltd. (NASDAQ:CTEL) provides fixed telecommunications networks and international telecommunications services for residential and corporate customers. CTEL gets F’s in Earnings Growth and Operating Margin Growth as well. For more information, get Portfolio Grader’s complete analysis of CTEL stock.

HKTV also gets F’s in Earnings Growth and Operating Margin Growth. For more information, get Portfolio Grader’s complete analysis of HKTV 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.