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

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

Tessera Technologies, Inc. (TSRA) invests in, licenses and delivers miniaturization technologies for electronic devices. TSRA also gets F’s in Earnings Growth, Earnings Momentum, Analyst Earnings Revisions, Equity, Cash Flow and Sales Growth. Shares of the stock have declined 2% since January 1. This is worse than the Nasdaq, which has remained flat. For more information, get Portfolio Grader’s complete analysis of TSRA stock.

Empire Resorts, Inc. (NYNY) is a gaming and resort management company. NYNY gets F’s in Earnings Growth and Equity as well. For more information, get Portfolio Grader’s complete analysis of NYNY stock.

PMFG, Inc. (PMFG) is a provider of custom engineered systems and products designed to help ensure that the delivery of energy is safe, efficient and clean. PMFG gets F’s in Earnings Growth, Analyst Earnings Revisions, Cash Flow and Sales Growth as well. Since January 1, PMFG has fallen 26.7%. For more information, get Portfolio Grader’s complete analysis of PMFG stock.

Tower Group International Ltd. (TWGP) is a provider of property and casualty insurance products and services. TWGP gets F’s in Earnings Growth, Earnings Momentum, Equity, Cash Flow and Sales Growth as well. For more information, get Portfolio Grader’s complete analysis of TWGP 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.