The overall ratings of 4 Semiconductors & Semiconductor Equipment stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Cavium, Inc. (CAVM) earns a D this week, moving down from last week’s grade of C. Cavium, Inc. designs, develops and markets semiconductor processors for intelligent and secure networks. For more information, get Portfolio Grader’s complete analysis of CAVM stock.

Nanometrics Incorporated’s (NANO) rating weakens this week, dropping to a D versus last week’s C. Nanometrics Incorporated manufactures film thickness and overlay metrology systems. For more information, get Portfolio Grader’s complete analysis of NANO stock.

Xcerra Corporation (XCRA) declines this week from a D to a F. The company also gets F’s in sales growth, earnings growth, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of XCRA stock.

STMicroelectronics NV ADR RegS (STM) gets weaker ratings this week as last week’s D drops 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 surprise. 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.