What happened

Shares of STMicroelectronics (NYSE:STM) rose 12.5% in September 2017, according to data from S&P Global Market Intelligence. The surge rested entirely on Apple 's (NASDAQ:AAPL) launch of the iPhone X, which is widely expected to contain a large number of STMicro chips.

So what

According to Tony Stoss, an analyst with Wall Street firm Craig-Hallum, the iPhone X's facial recognition features are likely to depend on STMicro's hardware solutions, pushing the company's chip content up from roughly $4 per handset in earlier models to $7 per phone this time. Since analysts expect Apple's preorders for the iPhone X to exceed 50 million units, that adds up to a potential $150 million revenue boost for the chip supplier.

The Apple iPhone X, splashing through some water.

Image source: Apple.

Now what

No single customer accounted for more than 10% of STMicro's annual sales in any of the last three fiscal years, but the company does list Apple as a major customer in SEC filings. A $150 million top-line boost from the iPhone X would be a significant change, considering that STMicro's quarterly revenues tend to land in the $1.8 billion to $1.9 billion range.

That being said, we won't actually know what chips the iPhone X is built around until the first actual handsets are shipped out in November. STMicroelectronics is a market leader, but not the only game in town for special camera technologies.

And since the stock is trading at an overly rich 47 times trailing earnings today, most investors might be better off on the sidelines until we know more about the iPhone X technology.