This week, the overall grades of 4 Semiconductors & Semiconductor Equipment stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Skyworks Solutions, Inc.’s (SWKS) rating worsens to a D from the company’s C rating a week ago. Skyworks Solutions, Inc. is an innovator of analog and mixed-signal semiconductors. For more information, get Portfolio Grader’s complete analysis of SWKS stock.

Qorvo, Inc.’s (QRVO) rating weakens this week, dropping to a D versus last week’s C. The company also gets F’s in operating margin growth. For more information, get Portfolio Grader’s complete analysis of QRVO stock.

Cree, Inc. (CREE) is having a tough week. The company’s rating falls from a C to a D. Cree, Inc. develops and manufactures semiconductor materials and devices. The company also gets F’s in sales growth and earnings revisions. For more information, get Portfolio Grader’s complete analysis of CREE stock.

Sigma Designs, Inc. (SIGM) earns a D this week, moving down from last week’s grade of C. Sigma Designs, Inc. provides integrated system-on-chip solutions for the internet protocol television, connected media player, prosumer and industrial audio/video, connected home technologies and other markets. The company also gets F’s in earnings growth. For more information, get Portfolio Grader’s complete analysis of SIGM 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.