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

WNS Holdings (NYSE:WNS) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. WNS provides comprehensive data, voice and analytical services that are underpinned by its expertise in its target industry sectors. The stock currently has a trailing PE Ratio of 32.90. To get an in-depth look at WNS, get Portfolio Grader’s complete analysis of WNS stock.

The rating of Western Union (NYSE:WU) slips from a C to a D. Western Union is engaged in global money transfer and payment services. The stock price has fallen 35.1% over the past month, worse than the 3.2% decrease the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of WU stock.

Cardtronics (NASDAQ:CATM) is having a tough week. The company’s rating falls from a C to a D rating. Cardtronics provides ATM management and equipment-related services to large and small retail merchants operators of facilities such as shopping malls and airports. The stock gets F’s in Earnings Growth, Earnings Momentum, and Margin Growth. Wall Street appears to agree with the stock downgrade, with share prices dropping 17.5% over the past month. For a full analysis of CATM stock, visit Portfolio Grader.

Computer Sciences (NYSE:CSC) earns a D this week, falling from last week’s grade of C. Computer Sciences offers services to clients in the commercial and government markets. The stock gets F’s in Earnings Growth, Cash Flow, and Margin Growth. For more information, get Portfolio Grader’s complete analysis of CSC 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.