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

Stocks fell sharply for a second straight day Thursday as August is turning into a dreary month for the equity markets. While some of the selling can be chalked up to fears of the Fed's loose-money policy coming to an end, escalating violence in Egypt also roiled the investment world. The S&P 500 Index (SNPINDEX:^GSPC) dropped 24 points, or 1.4%, closing at 1,661.

Uncharacteristically, the $130 billion Cisco Systems (NASDAQ:CSCO) led the index's decline, slumping 7.2% as Wall Street made its displeasure with the company's earnings call quite clear. The phrase "Investors buy the future, the past is not for sale" has not been epitomized as clearly as it was today with Cisco's shares. Sales actually beat expectations this quarter, but the company's guidance was below expectations and the networking giant cut roughly 5% of its workforce. 

JDS Uniphase (NASDAQ:VIAV), also in the communication devices market, lost 5.5%. JDS investors often look to Cisco's performance as a gauge for how they can expect future business to go, and today Cisco didn't do JDS investors any favors. Though the two companies are similar, JDS Uniphase, which is about 1/40th the size of Cisco by market cap, is much more vulnerable to shifts in the economy. Cisco's job cuts today, for example, would have amounted to about 80% of JDS's workforce. 

Lastly, Micron Technology (NASDAQ:MU) shed 4.7% as R.W. Baird downgraded the chip maker after doing some supply chain research in Asia. Both Intel and Micron were downgraded from a buy to a neutral rating. Though Micron has successfully entered into the smartphone market, it still has exposure to the PC market. Weaker demand in the PC market and slowing smartphone sales threaten to leave Micron with high chip inventories later in the year, according to the report. Though today's news certainly isn't bullish, anyone who's owned the stock this whole year has seen shares more than double in 2013 alone.

Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter @divinebizkid and on Motley Fool CAPS @TMFDivine.

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