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

This week, Skyworks Solution (NASDAQ:SWKS) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Skyworks Solutions is an innovator of analog and mixed-signal semiconductors. The stock price has dropped 18.8% over the past month, worse than the 2.4% decrease the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of SWKS stock.

IXYS Corp. (NASDAQ:IXYS) ratings are on the decline this week as the company earns a F (“strong sell”). Last week, it received a D (“sell”). IXYS designs, develops, and markets power semiconductors. The stock gets F’s in Earnings Momentum, Earnings Revisions, and Sales Growth. For a full analysis of IXYS stock, visit Portfolio Grader.

This week, Kulicke & Soffa

‘s (NASDAQ:KLIC) rating worsens to a D from the company’s C rating a week ago. Kulicke & Soffa designs, manufactures, and markets capital equipment, related spare parts, and packaging materials used to assemble semiconductor devices. The stock also rates an F in Sales Growth. Share prices fell 15.8% over the past month. To get an in-depth look at KLIC, get Portfolio Grader’s complete analysis of KLIC stock.

Pericom Semiconductor (NASDAQ:PSEM) gets weaker ratings this week as last week’s C drops to a D. Pericom Semiconductor designs, develops, and markets interface integrated circuits for the transfer, routing, and timing of high-speed digital and analog signals. The stock gets F’s in Earnings Growth, Earnings Revisions, Margin Growth, and Sales Growth. The stock price has fallen 7.2% over the past month. For more information, get Portfolio Grader’s complete analysis of PSEM 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.