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 JDS Uniphase (VIAV -0.92%) are trading 12% higher today after the company announced its plans to split into two independent publicly traded companies with a pre-market press release.

So what: JDS Uniphase will separate into two as-yet-unnamed companies comprising its core business segments: One will produce optical components and commercial lasers, and the other will focus on networking services, particularly optical security. In its recently completed 2014 fiscal year, the businesses that will comprise JDS' optical-components segment brought in $794 million in revenue, and those comprising networking segment generated $950 million. According to the press release, this move should save roughly $50 million between the two new companies, which will begin operating as stand-alone entities no later than the third quarter of 2015. However, the company will be forced to spend between $75 million and $100 million in one-time charges to effect the split.

Now what: JDS Uniphase's optical components and networking services segments each brought in similar revenues last year, but it's the inclusion of optical-security services in the networking segment that makes it both larger and likely to be more profitable. Last year, JDS' optical-components segment produced an operating margin of 11.8%, while networking services pulled down a similar operating margin of 10.7%. Optical security, on the other hand, had an operating margin of 35.9%, giving the combined services company an overall operating margin of 16%.

It's important to keep in mind, however, that JDS' optical-components segment is the only segment that seems to actually be regularly growing. The following chart tracks each segment's top-line growth for the past few years. See if you can spot a pattern:

Segment

2014 Growth Rate

2013 Growth Rate

2012 Growth Rate

2011 Growth Rate

Optical components

7%

5.8%

(9%)

54.4%

Networking services

2.7%

(3.4%)

(6%)

24.9%

Optical security

(2.4%)

(0.2%)

(2.2%)

4%

Source: JDS Uniphase annual reports.

JDS' optical-components segment failed to grow in only one of the past four years, and in every other year, it was the fastest-growing segment in the company. Investors who have been waiting for this company to reward their patience -- shares are down 50% in the past decade despite a 150% rise in revenue due to the company's struggles to turn a profit -- might do better to focus on the optical-components company and treat the services company more warily.