With so many companies across a wide variety of sectors suffering the wrath of volatile investor sentiment, it's easy to feel discouraged about the prospects of your portfolio in the current moment. However, when you're investing in quality stocks for five years, 10 years, 15 years -- or even longer -- the near-term environment is just a blip on the radar when compared to the broader scope of your investment journey. 

If you have $20,000 to invest long-term in stocks, here are three to consider putting at least some of that money toward today.

1. DexCom

DexCom (DXCM 0.33%) may not be a household name like some other healthcare stocks, but its products are a regular fixture of everyday life in millions of households globally.

The company's business model is simple. It manufactures and sells continuous glucose monitoring devices (CGMs). These devices are used by both type 1 and type 2 diabetics to track glucose levels and mitigate adverse blood sugar events.

Not only do these products generate robust demand by nature of the patients they serve, but DexCom wields control of roughly half of the entire CGM market worldwide. This has proven a catalyst for strong investor returns, not to mention revenue and profits.

Looking at the company's growth over the past three years, DexCom's annual revenue and net income have jumped by 66% and 53%, while the stock has generated an eye-popping total return of nearly 100%. With the growing prevalence of diabetes and the need for effective CGM devices on the rise, DexCom is ideally suited to meet this expanding need and increase its share of this lucrative market. 

2. Amazon 

Amazon (AMZN -1.14%) may be struggling against the headwinds of a volatile global economy and negative sentiment against tech stocks, but that doesn't mean this household name has exhausted its growth potential. Stepping back from the events of the past few quarters, the company still dominates two of the most profitable, rapidly expanding industries on the planet.

Of course, I'm referring to its share of the multi-trillion-dollar e-commerce industry -- Amazon boasts a 14% share globally and a 50% share in the U.S. Plus, Amazon leads the global cloud computing industry -- a $217 billion market, of which it currently controls 34%.

Even in the current environment, investors who held on to Amazon over the past five years would have experienced a total return of about 56%, with the company growing its top and bottom line by 164% and 1,000% during that same period.  

This is a company that has ridden out more than its fair share of market and economic storms. Amazon's notable presence in the e-commerce and cloud computing spaces, not to mention its diverse collection of businesses that span industries from healthcare to entertainment, all bode well for its durable growth story in the years ahead. 

3. Airbnb 

Before the pandemic, Airbnb (ABNB 1.09%) controlled roughly 20% of the vacation rental market in the U.S. alone and has successfully increased its share since that time. Meanwhile, in 2021, the global vacation rental space hit a valuation of $75 billion.

Taking Airbnb's 2021 revenue of $6 billion -- which includes experiences booked but largely stems from vacation rental fees -- would give the company a roughly 8% share of the global vacation rental market. Given that this fast-growing space is on track to hit a valuation of $119 billion by 2030, this certainly portends well for Airbnb's future growth prospects.

Not only has the high-growth business rapidly moved to profitability -- the third quarter was its most profitable ever, to the tune of $1.2 billion -- but it continues to grow revenue at a rapid clip. Its third-quarter revenue jumped 30% compared to the year-ago period.

Beyond the favorable tailwinds driving the vacation rental industry, the fact that Airbnb caters to a much broader consumer base than short-term travelers (20% of all gross bookings are stays of 28 days or more) bodes well for its ability to deliver sustained returns over the long term through a variety of market cycles.