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.

Happy holidays! It's Christmas and investors are showing their good cheer, as stocks opened up this morning, with the S&P 500 and the narrower Dow Jones Industrial Average (^DJI -1.42%) rising 0.44% and 0.40%, respectively, at 10:15 a.m. EST. The largest weighting in the S&P 500, Apple (AAPL -0.15%), is pulling the index higher, on the iPhone maker's Sunday announcement that it has finally struck an agreement with the world's largest telecom carrier, China Mobile (CHL).

Shares of Apple were up 3.1% at 10:15 a.m. EST on the announcement of a multiyear agreement that will make the iPhone 5S and 5C available on China Mobile's 3G and 4G networks. Equally important, China Mobile's retail distribution network will carry both handsets. The agreement is certainly a positive development for Apple, but does it warrant today's share price pop? After all, the agreement was heavily anticipated; On Dec. 3, the news that a China Mobile subsidiary website was accepting iPhone registrations sent the shares up 2.7%.

760 million...
is the current number of China Mobile customers, making it far and away the largest mobile network in the world. That's a huge number on the face of it -- it's nearly 2.5 times the U.S. population, after all -- which has fueled dreams of moonshot-type growth for some Apple investors. That's understandable, but the truth of the matter is that it's not relevant to this agreement. The next number provides some context to help understand why.

$9,055...
was China's gross domestic product per capita in 2012 (for reference, U.S. GDP was $51,704.) When the iPhone 5S and 5S were launched in September, the retail price in China for the lower-end 5C was set at $733, or roughly one month's domestic product! (Furthermore, the GDP per figure above is adjusted for the relative cost of living; strictly on the basis of exchange rates, the number falls to $6,071.) Those numbers ought to make it clear that China Mobile's entire customer base is not Apple's potential market for the iPhone, which is a premium product at a premium price. (Note, however, that the companies have not yet disclosed the pricing of the iPhones for China Mobile.)

20...
is the number of 4G handsets Citigroup expects will launch in the first half of 2014, most of which will sell for roughly $165 -- well below the price of even the lower-end iPhone 5C.

100 million...
is the number of Chinese people who can afford a premium product such as an iPhone, Benedict Evans of Enders Analysis told Bloomberg News.

45 million...
is the number of unlocked iPhones being used on China Mobile's networks, according to the network operator, so some demand for Apple handsets has already been met.

Make no mistake about, this deal is wonderful news for Apple and its shareholders, but it may not meet the expectations that some investors have for the agreement.