According to Apple CEO Tim Cook, the current iPhone lineup is selling well in China regardless of its recent economic slowdown. Image source: Flickr user Karlis Dambrans.

If you've been following the stock market recently, you're well-aware the past week has been unkind to investors. And although the carnage is reminiscent of 2008, the cause is entirely different. As opposed to the bursting of the housing bubble that originated from the biggest banks on Wall Street and spread to the entire world, this particular sell-off seems to have originated nearly 7,000 miles away in Beijing.

Recently, the People's Bank of China slashed its guiding rate versus the dollar for three straight days. These cuts, which make its exports more attractive, were widely considered to counteract the economic slowdown gripping the country. On the other hand, however, China presents a double-whammy for U.S. companies looking to grow revenue there, as foreign goods are more expensive amid an economic slowdown.

On the surface, this sounds like bad news for Apple (AAPL 1.27%) investors, as the company has become increasingly reliant on China for growth. Over the past three quarters, the company has reported 70%-plus revenue growth in The Middle Kingdom, and last quarter more than one out of every four dollars Apple booked in revenue came from China. Here's a visual representation:

Source: Apple's 10Qs. Revenue figures in millions. China revenue as percentage of total calculation = [Greater China Revenue/(Total Revenue Ex-China + Greater China Revenue)]. 

That said, it seems CEO Tim Cook really wants investors to know that Apple is OK in China. And that's what he emailed Mad Money host Jim Cramer.

A big departure from the Apple of yesteryear
In an email addressed to the media personality, and released to the public via CNBC anchor Carl Quintanilla, Cook seeks to assure skittish investors in regard to the company's future performance in China. Per Cook: "I get updates on our performance in China every day, including this morning, and I can tell you that we have continued to experience strong growth for our business in China through July and August." And while the update is reassuring, for those following Apple this is somewhat unprecedented for Cupertino to address concerns in this manner. Here's the email in its entirety as posted by Quintanilla: 

Under Cook's predecessor, Steve Jobs, the company was notoriously secretive, with an almost-singular product focus, believing shareholders would ultimately be rewarded if the company executed. Cook appears to balance the needs of all stakeholders -- including customers, employees, and shareholders -- more than Jobs did. So while a mid-quarter email seems odd, even for Cook, it's not totally out of character for the company to engage shareholders.

How will Apple fare in China?
The question for investors is whether Apple can continue to swim against the smartphone tide in China. Recently, data analytics firm Gartner reported that China experienced a 4% year-over-year drop in smartphone unit sales in the recently reported second quarter, as the effects from the recession and a maturing market weighed on the country. During that period, Apple's third fiscal quarter, the company reported greater China iPhone unit sales growth of 87% year on year among the 123% revenue increase.

In the next quarter, Apple's fiscal fourth, I expect Apple's year-on-year China revenue comparables to continue their eye-popping trend, as the nearly $5.8 billion produced in Q4 2014 should be easily surpassed. After that, Apple's growth rates in China should moderate, but the company and its CEO think the LTE trade-up and continued middle-class growth should continue to drive upgrade cycles and iPhone sales. More recently, Apple's proved that it can execute in mature, slower-growth markets and in contracting economies. Will China really be that different?