Rivian (RIVN 7.80%) has grown tremendously since going public in 2021. Since then, sales have grown by more than 515,000%, from nearly zero to more than $5 billion. More recently, however, sales growth has been sluggish. Since June 2025, for instance, revenue has increased by just 2.1%.

But here's the thing: Over the next three years, Rivian has the opportunity to grow sales by more than 300%! How is that possible? There's one critical growth catalyst every electric vehicle (EV) stock investor should pay very close attention to.

In 2026, everything will change for Rivian

If you want to understand how to scale an EV maker into a $1 trillion behemoth, just look at Tesla (TSLA 6.18%). The EV maker started with its Roadster model: a high-performance, high-priced vehicle accessible only to high-end buyers. This vehicle had limited sales, but it put Tesla on the map, earning it a reputation for quality.

Then came the Model X and Model S. These were slightly more affordable, but often still cost customers more than $100,000 out the door. The form factors -- a sedan and SUV -- were much more popular, however. These two models brought Tesla to households across America. Yet sales were still limited versus nearly every other automotive stock.

Everything changed in 2016 when the Model 3 was unveiled. It was Tesla's first mass-market vehicle with a price tag under $50,000. Within a few years, the Model Y was also launched on the same platform at a similar price point.

From 2010 to 2016, Tesla's sales grew from just $100 million to around $4 billion. From 2016 to 2022, however, Tesla sales zoomed from $4 billion to more than $50 billion!.

What was the cause? The bulk of this growth came almost exclusively from the Model 3 and Model Y. Today, those two models account for more than 90% of Tesla's vehicle revenue.

Remarkably, Rivian is on a very similar path to growth. One of its first vehicles was a delivery van that sold only to a limited set of buyers like Amazon. But the company also released two versions of a truck: the R1T and R1S. These luxury trucks were priced similarly to the Model S and Model X. From 2021 to 2025, these vehicles helped bring Rivian's sales base from essentially zero to around $5 billion -- very close to where Tesla was before the introduction of its mass-market vehicles.

This all sets to stage for 2026 when Rivian expects to begin shipments of three new mass-market vehicles: the R2, R3, and R3X. Critically, all are expected to have price points starting below $50,000.

Self-driving electric vehicle

Image source: Getty Images.

Is it time to load up on RIVN stock?

Rivian will very likely see its sales growth soar over the next three years. According to an update earlier this summer, production for the R2 appears on track, with many of the critical infrastructure and testing milestones already achieved. If Tesla's growth trajectory is any indication, these cheaper models will make Rivian vehicles accessible to tens of millions of new buyers. Sales growth of 300% or more over the next three years is actually a conservative estimate based on what Tesla achieved.

Should you load up on Rivian stock before these new models launch? You can certainly make the case that you should. Rivian stock trades at just 2.7 trailing sales versus Tesla's premium valuation of 12.9 times sales. And while Tesla is exposed to other industries like energy storage, as well as longer-term opportunities like robotaxis, the bulk of its revenue still comes from car sales, making it a reasonable comparable.

Despite its lofty valuation, Tesla is actually expected to see sales fall by 5% this year. Rivian, meanwhile, is expected to grow sales by just 6.5%.

Rivian's sales ramp-up is just around the corner. But the current valuation doesn't seem to price that in just yet. Getting in early helps lock in a value price for what should soon be a reinvigorated growth stock.