This week, the ratings of three Tech Services stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

WEX Inc. (NYSE:WEX) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. Winland Electronics designs and manufactures custom electronic controls and assemblies mainly for original equipment manufacturer customers, providing services from early concept studies through complete product realization. The stock price has fallen 6.9% over the past month, worse than the 1.7% decrease the S&P 500 has seen over the same period of time. The stock has a trailing PE Ratio of 27.30. To get an in-depth look at WEX, get Portfolio Grader’s complete analysis of WEX stock.

VeriFone Systems, Inc. (NYSE:PAY) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). VeriFone is engaged in the design, marketing, and service of transaction automation systems that enable secure electronic payments among consumers, merchants, and financial institutions. The stock receives F’s in Earnings Growth, Earnings Momentum, Earnings Revisions, and Margin Growth. The stock’s trailing PE Ratio is 142.60. For more information, get Portfolio Grader’s complete analysis of PAY stock.

The rating of Teradata Corporation (NYSE:TDC) declines this week from a C to a D. Teradata provides customers with enterprise data warehousing, including enterprise analytic technologies and services through software, hardware, and related business consulting and support services. The stock currently has a trailing PE Ratio of 25.90. To get an in-depth look at TDC, get Portfolio Grader’s complete analysis of TDC 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.