The ratings of 6 Semiconductors & Semiconductor Equipment stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Cavium, Inc. (CAVM) slips from a D to a F this week. Cavium, Inc. designs, develops and markets semiconductor processors for intelligent and secure networks. The company also gets F’s in earnings revisions. For more information, get Portfolio Grader’s complete analysis of CAVM stock.

Cabot Microelectronics Corporation (CCMP) gets weaker ratings this week as last week’s C drops to a D. Cabot Microelectronics Corporation supplies high-performance polishing slurries used in the manufacture of advanced integrated circuit (IC) devices within the semiconductor industry. The company also gets F’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of CCMP stock.

Slipping from a C to a D rating, IXYS Corporation (IXYS) takes a hit this week. IXYS Corporation designs, develops, and markets power semiconductors. For more information, get Portfolio Grader’s complete analysis of IXYS stock.

Sigma Designs, Inc. (SIGM) declines this week from a C to a D. 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 revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of SIGM stock.

Xcerra Corporation (XCRA) earns a D this week, moving down from last week’s grade of C. The company also gets F’s in sales growth, earnings growth, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of XCRA stock.

STMicroelectronics NV ADR RegS (STM) experiences a ratings drop this week, going from last week’s D to a F. STMicroelectronics NV ADR RegS is a designer, developer, manufacturer and marketer of semiconductor products. The company also gets F’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of STM 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.