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.

Dow component and economic bellwether General Electric this morning reported fourth-quarter earnings per share that were in line with Wall Street expectations, so it is perhaps fitting that stocks should open roughly unchanged, with the S&P 500 and the narrower Dow Jones Industrial Average (^DJI 0.67%) down 0.18% and up 0.04%, respectively, at 10:15 a.m. EST.

Today is the day that Apple (AAPL 0.51%) enthusiasts in China -- and many Apple shareholders everywhere -- have been anticipating for some time, as the iPhone went on sale on China Mobile's network. China Mobile is the world's largest mobile carrier, with 763 million customers at the end of last November.

However, China Mobile is hardly pushing the iPhone at this stage, selling the iPhone 5S and 5C at unsubsidized prices of 5,288 yuan (roughly $870) and 4,488 yuan (roughly $740), respectively -- the same prices available from Apple stores or the Apple website in China.

The nation's No. 2 and No. 3 carriers, China Telecom and China Unicom, already offer the iPhone on their networks and have recently cut the price of their contracts in anticipation of China Mobile's iPhone launch. China Telecom, for example, has cut the rate on its 24-month contract for the 16GB iPhone 5S by up to 24%. China Mobile is banking on the 4G network it is building to leapfrog its rivals' technology and attract high-end users, but for Apple those are "cannibalization" sales.

On Wednesday, China Mobile reported 1.3 million advance orders for iPhones on its website, but checks made by Reuters showed there were multiple registrations with fake ID numbers. Little wonder, then, that one equity research analyst told The New York Times that advance orders would only translate into one-third as many firm orders.

Finally, keep in mind that there exists a substantial gray market for iPhones smuggled into mainland China from Hong Kong. China Mobile itself says there are already 45 million iPhone users on its network -- more than 60% of the iPhones in use in China, by one estimate!

Apple CEO Tim Cook was in Beijing on Friday to mark the occasion at the opening of a China Mobile retail store, underscoring the importance of the China Mobile agreement to his company. However, Apple is taking the long-term view here (as well it should): It took several years to negotiate this deal with China Mobile and it will take several more before the payoff really becomes apparent. Sure, we may witness a short-term bump in sales in the first quarter, but, for all the hype surrounding this deal, it's a long-term bet, not a short-term catalyst for a significant rerating in the shares.