Qualcomm (NASDAQ:QCOM) shareholders are hurting right about now. Shares have fallen to four-year lows after the company reported fiscal fourth-quarter earnings last week.

Total revenue fell 18% to $5.5 billion, and net income fell a painful 44% to $1.1 billion. MSM chip shipments came in better than expected at approximately 203 million. Throughout fiscal 2015, Qualcomm returned a solid $14 billion in capital to investors, mostly through share repurchases. But overall, investors were not impressed.

I don't mean to add insult to injury, but the mobile chip giant's most recent earnings release highlights several of the reasons why I personally decided to sell my own shares a few months back. Many of the risk factors I was concerned about as a shareholder presented themselves last quarter.

The chip business
In no uncertain terms, 2015 has been a brutal year for Qualcomm's QCT chip segment. QCT took a double whammy in the form of losing Samsung's (NASDAQOTH:SSNLF) Galaxy S6 and Apple's (NASDAQ:AAPL) share gains. The loss at Samsung put pressure on revenue, while Apple's success in the high-end smartphone market translated into margin pressures since Qualcomm only sells less-profitable modems into the iPhone.

Source: SEC filings. EBT = earnings before tax.

Qualcomm is hoping its upcoming Snapdragon 820 can help turn things around. The newer chip should deliver substantial improvements compared to the Snapdragon 810. In an effort to catch up to Apple's 64-bit A7, which completely caught the industry off guard, Qualcomm hastily implemented stock ARM cores instead of using its own custom cores like it had always done before. Among other reasons, this contributed to Samsung passing on the 810.

The potentially good news for investors is that QCT's darkest days may be behind it. The chip business could be in the process of bottoming out as we speak.

The licensing business
Qualcomm has been struggling for quite some time with getting Chinese OEMs to play by the rules. The company has long suspected that many smartphone vendors were underreporting shipment volumes in an effort to reduce the royalty bill owed to Qualcomm. More troubling is that these problematic underreporting OEMs are gaining share recently, according to CEO Steve Mollenkopf.

Here's President Derek Aberle with some additional color:

For the fourth quarter of fiscal 2015, the global 3G/4G device sales were in line with our expectations but total reported device sales for the quarter came in below the low end of our guidance range, primarily as a result of the Chinese licensees I just mentioned refusing to report royalties, slower than previously expected progress on signing license agreements covering 3-mode devices, and Chinese OEMs that are either unlicensed or under-reporting royalties growing at a faster rate than the overall market, and thereby gaining share. These factors resulted in approximately $200 million less in QTL revenue for the fourth quarter as compared to our prior expectations and lower than expected QTL operating margin.

There have also been delays in inking new license agreements. On top of that, there is some pretty intense price competition going on in China right now at the low end of the market, and since Qualcomm's royalty revenue is based on the average selling prices of devices, even the revenue it is collecting is under pressure.

What's in store for 2016?
Considering the tough 2015 Qualcomm has experienced, the company is being set up for easier comparisons for 2016. It's a little disconcerting that Qualcomm has now stopped issuing annual guidance and will now only provide quarterly forecasts, suggesting that visibility is limited.

But if Qualcomm can win back Samsung in the Galaxy S7, which it reportedly has, and make continued progress with getting Chinese licensees in compliance, the company might be able to stage a comeback next year.

Evan Niu, CFA, owns shares of Apple. The Motley Fool owns shares of and recommends Apple and Qualcomm. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.