Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Conexant Systems (Nasdaq: CNXT) popped more than 10% in intraday trading today.

So What: Early in the morning, the ComTex SmarTrend service noted that Conexant carries a higher earnings yield than any other semiconductor stock, edging out Micron Technology (NYSE: MU) and Integrated Silicon Solutions (Nasdaq: ISSI) by a nose-hair each. That could indicate a cheap stock, which may explain why the market reacted in moderately heavy volume.

Now What: Much like an unsustainable dividend yield, a high earnings yield can also highlight a problem stock. Even the SmarTrend note is "bearish" on Conexant. It's notoriously difficult to even get a handle on what Conexant does for a living. Better-run rivals such as Micrel (Nasdaq: MCRL) or Cirrus Logic (Nasdaq: CRUS) should rank higher on your research list, despite their higher P/E ratios and lower earnings yields.