Since debuting as an online bookseller in 1994, (NASDAQ:AMZN) has gone on to become a worldwide e-commerce juggernaut. Early investors in the company after it went public in 1997 have been richly rewarded, as the stock has grown more than 80,000%. Finding companies with that type of potential can be like finding a needle in a haystack.

With that in mind, we asked three Motley Fool investors to help choose top companies that they believed could reward investors with massive returns akin to Amazon's. They offered convincing arguments for Shopify (NYSE:SHOP), Novavax (NASDAQ:NVAX), and Aptiv (NYSE: APTV).

Finger reaching to press a green lighted button depicting a rocketship.

Image source: Getty Images.

Riding Amazon's coattails

Danny Vena (Shopify): To find a company that can generate returns similar to Amazon's, investors can look to the same retail shift that made the online retailer such a massive success. While e-commerce has taken a big bite out of brick-and-mortar sales, the trend has only just begun. According to the U.S. Department of Commerce, for the fourth quarter of 2017, e-commerce accounted for just 8.9% of total retail sales, up from about 3.5% a decade earlier.

E-commerce facilitator Shopify has everything a budding entrepreneur needs to develop and manage an online retail presence. The platform supplies more than 100 ready-to-use templates for designing a website, as well as 2,300 apps to help customize the experience. Shopify also helps merchants accept payments and ship and track their orders, and provides them with small-business loans to meet immediate cash flow needs. Providing these services allows its customers to concentrate on selling their wares.

The Shopify app featured on a tablet and smartphone.

Image source: Shopify.

In its quest to ease the burdens of online sellers, Shopify has been so successful that it now hosts more than 600,000 merchants in 175 countries. The company has produced year-over-year revenue growth exceeding 70% in each quarter since it went public in mid-2015. Shopify has yet to produce a profit, choosing instead to pour its resources into growth -- much as Amazon did in its early years.

In its first eleven quarters as a public company, Shopify's share price has gone up nearly 400%, but I believe it's just getting started. As more and more businesses come online, many will need the services that Shopify has to offer, giving the company a long runway of growth ahead.

Keep your eyes on the prize

George Budwell (Novavax): Novavax, a small-cap vaccine maker, has largely disappointed investors over the past two years, thanks to the late-stage failure of its experimental respiratory syncytial virus (RSV) vaccine for elderly adults. However, the company is far from dead, meaning that aggressively minded growth investors may want to circle back for a closer look.

Novavax's value proposition presently centers around its other ongoing late-stage trial for RSV in pregnant women, as well as its midstage flu vaccine candidate known as NanoFlu. The company is expected to release top-line results for its maternal RSV immunization study in 2019, setting the stage for a possible regulatory filing in 2020. If successful, this vaccine should easily generate well over a billion dollars in revenue at peak, given the enormous size of the target market and tremendous unmet medical need.

Doctor using syringe to draw medication from a vial

Image source: Getty Images.

On the flu front, Novavax is gearing up to advance NanoFlu into a midstage trial shortly, and the company already appears to have an eye on commencing a pivotal stage by 2019. The point is that Novavax could very well have two megablockbuster vaccines on the market within the next two and a half years.

The downside is that as things stand now, the company simply doesn't have enough cash to realize these lofty goals. Even after its latest capital raise of about $50 million after deducting fees, Novavax arguably has less than two years worth of cash on hand. Therefore, the company either needs to find a partner willing to help out, or it'll end up diluting shareholders yet again in the not-so-distant future.

All told, Novavax offers a stellar upside if things work out, but the need for additional capital is a serious risk that growth-hungry investors shouldn't overlook.

Driverless goldmine

Daniel Miller (Aptiv): To even be uttered in the same breath as Amazon in regard to massive long-term returns, a company has to be poised to thrive on an emerging megatrend. If there's a predictable trend in the unpredictable automotive industry, it's this: Driverless vehicles are on their way. And it also looks like auto suppliers such as Aptiv could offer investors a great way to play the megatrend.

"Those companies providing technology which supports an autonomous, connected, shared and electric transportation system are well positioned to experience heightened levels of profitable growth over the long term," said Thomas Fitzgerald, associate fund manager at EdenTree Investment Management, according to Reuters.

Closeup of a car headlight

Image source: Aptiv.

Aptiv specializes in developing the exact technology Fitzgerald refers to. If you haven't heard of Aptiv before, it specializes in providing end-to-end solutions between smart vehicle architecture and smart mobility solutions. In other words, the company develops the software, sensing, computing, signal, power distribution, and overall connectivity technology that will be the basis for driverless-car user experience, safety, and entire autonomous systems.

Driverless cars could become a huge part of solving problems such as crash fatalities, greenhouse-gas emissions, and inefficient transportation, among other issues. An Intel report released last year predicts that driverless vehicles will generate a $7 trillion annual market by 2050. If Aptiv becomes a leader in developing driverless vehicle technology -- and that's a sizable if -- it's one of few companies that could actually put Amazon's returns to shame.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.