When a business is making headway in a massive and uncontested global market, shareholders reap the benefits. The earlier you invest in those players and the longer you hold the shares, the more time your money will have to grow.

In particular, there are two companies penetrating large markets that are all but guaranteed to keep growing as long as the world's population does. Over the next decade, these companies plan to expand, entering some massive markets like China. The result could well be a run of wild growth over the next few years.

Let's take a closer look at two stocks with unstoppable growth potential over the next decade.

A person looks at a computer screen displaying a bar chart.

Image source: Getty Images.

1. Align Technology

Align Technology's (ALGN -2.69%) business model is simple: It sells its Invisalign tooth straighteners to dentists and orthodontists, who use its scanning and 3D modeling devices to adapt the straighteners to fit their patients -- thus eliminating the need to get traditional braces. 

In the last 10 years, Align's quarterly sales rose by 475%. In the first quarter of 2023 alone, it shipped more than 575,000 cases of its straighteners globally, yielding $943 million in revenue and nearly $136 million in free cash flow. International markets accounted for 47% of those sales, and in the coming years, that proportion will grow -- most likely by quite a bit -- alongside sales.

Management estimates as many as 500 million people globally could benefit from an Invisalign system. But only 15.1 million people have used them so far.

To bridge some of the gap between those two numbers, the company plans $200 million in capital expenditures during 2023 to beef up its manufacturing capacity. And given the success of its previous efforts to expand, there's reason to believe that it will succeed this time around, too.

The company only has $126 million in debt, and its cash holdings are $884 million.

The catch with Align is that its stock is super pricey. Its price-to-earnings (P/E) ratio is 78, which indicates that the market is anticipating that the company will grow much faster than average. So the stock carries the risk of being overpriced relative to the amount of growth that actually happens. That, in turn, could potentially cause its shares to collapse if there are a few bad quarters of business performance. If that risk doesn't bother you and you plan to hold long-term, buy away. 

2. STAAR Surgical 

Much like Align Technology, STAAR Surgical (STAA -2.48%) provides customers with technology that's better than the legacy solutions. In STAAR's case, the product is an implantable collamer lens (ICL) for long-term vision correction. Also, much like Align, STAAR has big plans for international expansion, and soon.

Anyone who uses either glasses or contact lenses is in this business' target market. Its lenses are implanted via a quick outpatient procedure, and they don't require any cleaning or regular upkeep. The company estimates that there are more than 2 billion nearsighted people who might be eligible for its lenses today -- and it expects there to be more than 5 billion by 2050. So it should have plenty of new customers in the future. And in the last 10 years, its quarterly net income rose by 874%, reaching $2.7 million in the first quarter of 2023.

Business is booming, and its competitors don't pose a major threat to its market share at present. Sales of its lenses have grown by at least 25% per year since 2019, and management expects $340 million in sales this year. Its entry into China will give STAAR access to the country's 1.2 million annual refractive-lens implantation procedures.

All told, this company's runway for growth is tremendous, and it won't need to make any big strategic changes to continue to capture market share. Unfortunately, STAAR's shares are valued even more expensively than Align's, with a P/E of 89. So the same caveats about price and risk apply here.