This week, four tech services stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

Gartner, Inc. (IT) is bumping up its rating from a C (“hold”) to a B (“buy”) this week. Gartner provides research and analysis on the computer hardware, software, communications, and related information technology industries. In Portfolio Grader’s specific subcategory of Equity, IT also gets an A. For more information, get Portfolio Grader’s complete analysis of IT stock.

Blackhawk Network Holdings, Inc. Class A (HAWK) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. For more information, get Portfolio Grader’s complete analysis of HAWK stock.

This is a strong week for Western Union Company (WU). The company’s rating climbs to B from the previous week’s C. Western Union is engaged in global money transfer and payment services. For more information, get Portfolio Grader’s complete analysis of WU stock.

This week, Convergys Corporation (CVG) pushes up from a C to a B rating. Convergys provides customer management business process outsourcing solutions for communications, financial services, technology, and other vertical markets in North America and internationally. For more information, get Portfolio Grader’s complete analysis of CVG 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.