Want to add massive long-term growth potential to your portfolio? Check out electric car stocks.

Many EV makers have seen their sales skyrocket in recent years. Yet their stock prices haven't always followed suit, creating several compelling buying opportunities over the years. This month looks like an especially great time to jump in.

If you want to buy into the world's adoption of EVs -- a story that is truly a multi-decade growth opportunity -- then these two stocks are for you. One you've likely heard of. But the other is a diamond in the rough.

Don't be shy about buying shares in Tesla

Perhaps the most popular EV maker in the world is Tesla (NASDAQ: TSLA). Its boisterous CEO, Elon Musk, is constantly making the news. And with nearly $100 billion in sales, Tesla dominates the EV industry of several major markets, the U.S. included.

You're likely already familiar with the company's lineup. Tesla offers premium models like the Roadster, Model X, Cybertruck, and the Model S. But it also offers a few mass-market vehicles. These are typically vehicles under the $50,000 price mark, a common benchmark for gleaning whether a car or truck will be accessible to the masses.

While Tesla does have exposure to other markets like energy generation and storage, more than 90% of its revenue is still tied to its EV business. And while its luxury models helped put it on the map, it really was its two mass-market models -- the Model Y and Model 3 -- that helped Tesla's sales grow by more than 1,000% over the past decade. After all, the volumes that can be achieved through a $50,000 car are perhaps an order of magnitude higher than what can be achieved with a $100,000 car.

Due to weaker-than-expected sales growth this year for the EV industry, the stocks of most EV producers have suffered. Tesla hasn't been immune to these pressures, but its valuation still doesn't look like an obvious bargain. Shares currently trade at 7.9 times sales -- roughly what they traded for nearly two years ago, when quarterly sales growth was around 30%.

But a bet on Tesla today isn't about the near term -- it's about the multidecade growth trajectory for EVs in general. The IEA forecasts EV demand to grow by double digits for decades to come. And Tesla has what most EV start-ups only dream of: access to capital.

So while the stock isn't as big of a bargain as the next stock on this list, Tesla is still a reasonable investment for those looking to bet on EV companies with the best chance of riding the long-term EV adoption wave.

This EV stock looks like a hidden gem

Want to invest in the next Tesla? Look no further than Rivian (NASDAQ: RIVN). The EV maker might not have the brand-name recognition of Tesla right now, but in the coming years, that could change quickly.

The company expects to release its first mass-market vehicles -- the R2, R3, and R3X -- beginning in 2026. And if Tesla is any indication, sales could quickly rise by 1,000% more in the years that follow.

Despite this impending sales ramp, Rivian shares trade at a steep discount to Tesla on a price-to-sales basis. What's going on?

As a smaller competitor with a sales base of just $5 billion, the market is understandably skeptical that Rivian can execute on its sales ramp. While Tesla is a success story, there have been many more bankruptcies in the EV space than successes. Rivian not only needs to raise billions in additional capital to support its launch plans, but also to scale up manufacturing capabilities greater than any other time in its history. And then, of course, it needs to produce cars that people love at a price point they can afford.

Due to these concerns, Rivian shares have fallen by roughly 55% in 2024, versus a much lesser 12% decline for Tesla shares. This has created a great buying opportunity this month for investors willing to take on extra risk in exchange for the high potential returns involved in identifying the next big EV brand.

Don’t miss this second chance at a potentially lucrative opportunity

Ever feel like you missed the boat in buying the most successful stocks? Then you’ll want to hear this.

On rare occasions, our expert team of analysts issues a “Double Down” stock recommendation for companies that they think are about to pop. If you’re worried you’ve already missed your chance to invest, now is the best time to buy before it’s too late. And the numbers speak for themselves:

• Amazon: if you invested $1,000 when we doubled down in 2010, you’d have $21,266!*

• Apple: if you invested $1,000 when we doubled down in 2008, you’d have $43,047!*

• Netflix: if you invested $1,000 when we doubled down in 2004, you’d have $389,794!*

Right now, we’re issuing “Double Down” alerts for three incredible companies, and there may not be another chance like this anytime soon.

See 3 “Double Down” stocks ?

*Stock Advisor returns as of October 7, 2024

Ryan Vanzo has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Tesla. The Motley Fool has a disclosure policy.

2 Top Electric Vehicle (EV) Stocks to Buy in October was originally published by The Motley Fool