Many people think that the only way to attract a fortune is to win the lottery. But over time, the magic of compound interest can help small sums become impressive amounts.

Unfortunately, millions of Americans still don't own any stocks at all. Whether or not that group includes you, take a close look at the growth stock below. While it will take time for its story to fully play out, the long-term returns could ultimately rival what could be achieved via the lottery.

Rivian has huge potential, but growth will take time

When I think about stocks with huge long-term potential, Rivian Automotive (RIVN -0.48%) instantly comes to mind. The company has a market capitalization of just $16 billion. That's peanuts compared to the largest electric vehicle (EV) stock in the world, Tesla, which has a market cap north of $1 trillion.

If Rivian reaches that size, a $10,000 investment would grow to more than $600,000! Even an investment of $100 would transform into $6,000. What are the chances that Rivian becomes the next Tesla? Pretty low, if we're being honest. Tesla is a rarity, succeeding in an EV industry that has seen lots of bankruptcies.

Building cars is capital intensive, and few companies are able to scale up fast enough to avoid insolvency. But when you look at what Rivian is doing, the risk-reward trade-off is significantly more attractive than playing the lottery.

The first thing an EV maker needs to do to replicate Tesla's success is to release models that are priced under $50,000. The Model 3 and Model Y -- with starting prices under $50,000 -- account for more than 90% of the company's vehicle revenue.

With only two high-priced luxury models at the moment -- the R1T and R1S, both of which can cost more than $100,000 depending on options -- Rivian is extremely handicapped when it comes to growth. The vast majority of buyers simply can't afford one.

All of this is set to change in 2026 when Rivian begins production of its first affordable model ever: the R2. The starting price is expected to be around $45,000. Tens of millions of new potential buyers should be able to afford one.

And management expects to follow the R2 with two models that will be even cheaper: the R3 and R3X. They are forecast to start production sometime in 2027, greatly improving Rivian's growth prospects.

How long might it take for the stock price to reflect this potential? That's where some patience will be needed.

Source: Getty Images

Long-term investors will profit the most from Rivian stock

Tesla's Model 3 started production in the summer of 2017. At the time, shares traded at roughly $25. The Model Y didn't begin production until the start of 2020, nearly three years after the Model 3. Still, in 2020, Tesla shares traded at just $30 -- hardly a huge return over that number of years.

But then everything changed. Once Model 3 and Model Y production grew large enough to scale up orders significantly, Tesla shares took off. By the start of 2021, they were approaching a price of $300.

The same patience will be needed with Rivian stock. The company has a bright future, with all the pieces in place to grow by leaps and bounds. But manufacturing vehicles -- especially vehicles that use specialized technology -- takes a long time to scale up. Once Rivian begins production of the R2, it may still take years for sales to scale up, to say nothing of seeing other models like the R3 and R3X appear.

There will be plenty of execution risks along the way. But with a market cap of just $16 billion, there's huge long-term potential in Rivian shares. And if all goes right, the most patient investors will see the biggest potential profits.