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 Oclaro (Nasdaq: OCLR) dropped as much as 10% in intraday trading today. There was no news directly involving this optical components maker.

So what: It's possible the sell-off is related to a disappointing earnings report from Tellabs (Nasdaq: TLAB), which also serves the telecom industry. Tellabs is down about 15% today, and a few other related companies, such as Finisar (Nasdaq: FNSR) and JDS Uniphase (Nasdaq: JDSU), are also trending lower.

Now what: Oclaro is scheduled to report earnings on Thursday morning. Investors are better off waiting for that and listening to the conference call -- rather than playing a guessing game based on other companies' earnings -- before making any buy or sell decisions.

Interested in more info on Oclaro? Add it to your watchlist by clicking here.

Fool analyst Rex Moore doesn't own any companies mentioned here. Try any of our Foolish newsletter services free for 30 days. True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community. The Motley Fool has a disclosure policy.