Want $1 Million in Retirement? Invest $100,000 in These 2 Stocks and Wait a Decade.

Only around 10% of American retirees have saved up more than $1 million in their nest eggs, according to the Federal Reserve's latest Survey of Consumer Finances. To join that club, many Americans need to invest their cash more effectively.

So, if you have some uninvested cash and at least a decade until retirement, you should consider buying a few high-growth stocks that have the potential to deliver multibagger gains. I believe two speculative plays -- Rivian Automotive (NASDAQ: RIVN) and CleanSpark (NASDAQ: CLSK) -- might just turn $100,000 into $1 million over the next 10 years.

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The unloved EV maker: Rivian Automotive

Rivian's stock trades more than 80% below its IPO price. The maker of electric pickups, SUVs, and delivery vans lost its luster as it struggled to ramp up its production. Rising interest rates also highlighted its steep losses and compressed its valuations.

Rivian more than doubled its production to 57,232 vehicles in 2023 as it overcame its supply chain constraints and ramped up the production of its in-house Enduro drive unit. However, it expects its production to flatline this year as it faces tougher macro headwinds and temporarily shuts down its main plant in Normal, Illinois, to upgrade its production capabilities. That outlook was disappointing, but it still expects to achieve a positive gross margin per vehicle by the fourth quarter of this year.

Looking ahead, Rivian plans to open a new $5 billion plant in Georgia, roll out its R2, R3, and R3X SUVs in 2026 and 2027, and fulfill Amazon 's big order for 100,000 electric delivery vans through 2030. It also launched a joint venture (JV) with Volkswagen earlier this year to develop new EV architecture and software. Volkswagen will invest up to $5 billion in Rivian and the JV as part of the deal.

Those developments indicate Rivian isn't down for the count yet. Analysts still expect its revenue to grow at a compound annual growth rate (CAGR) of 32% from 2023 to 2026. If it can hit those targets and continues to grow at a more moderate CAGR of 20% from 2026 to 2034, it could generate nearly $44 billion in revenue by the final year. That would represent a tenfold gain from its $4.4 billion in revenue in 2023 -- so investors might want to pick up this unloved EV stock while it's still trading at 2.5 times this year's sales.

The clean energy Bitcoin miner: CleanSpark

CleanSpark is the third-largest publicly traded Bitcoin miner after Marathon Digital and Riot Platforms . Unlike Marathon and Riot, which have both been criticized for using coal-fired and fossil fuel plants to mine Bitcoin, CleanSpark only uses low-carbon energy solutions like wind and solar.

That's because CleanSpark previously developed modular microgrids -- which funnel low-carbon power into storage, backup generators, and load management solutions -- for other companies. These microgrids can be used as stand-alone power sources or be plugged into a centralized grid.

In 2021, CleanSpark acquired the Bitcoin miner ATL Data Centers and optimized its mining operations with its microgrids. It subsequently expanded that business by acquiring and upgrading several more Bitcoin mining facilities. Its hash rate, which gauges the efficiency of its mining operations, rose from 1.01 EH/s (exahashes per second) at the end of fiscal 2021 (which ended in September 2021) to a whopping 20.4 EH/s at the end of June. It mined 3,614 Bitcoins in the first half of calendar 2024.

CleanSpark's future is tightly tethered to the future of Bitcoin. Assuming the cryptocurrency's price continues to rise, analysts expect the company's revenue to grow at a CAGR of 68% from fiscal 2023 to fiscal 2026. If it meets those expectations and continues expanding at a CAGR of 25% over the following eight years, it could generate $4.7 billion in revenue by fiscal 2034. That would be 26 times higher than its $168 million in revenue in fiscal 2023.

That might sound like a lofty target, but the bulls believe Bitcoin's price could still rise from about $61,000 today to over $1 million over the next few years. If that happens, CleanSpark would be well-positioned to generate millionaire-making gains, and it might be an undervalued growth play right now at less than six times this year's sales.

John Mackey, former CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Leo Sun has positions in Amazon. The Motley Fool has positions in and recommends Amazon, Bitcoin, and Volkswagen Ag. The Motley Fool has a disclosure policy .