Several developers of electric vertical take-off and landing (eVTOL) aircraft went public by merging with special purpose acquisition companies (SPACs) in 2021. At the time, many investors were dazzled by these companies' partnerships and rosy long-term expectations, even though they hadn't delivered any commercial aircraft yet.

The bulls believed these drone-like eVTOL aircraft would replace traditional helicopters because they were cheaper, greener, quieter, and easier to land in urban areas. The U.S. Air Force, major airlines, automakers, and ride-sharing companies all plan to use these aircraft as air taxis. From 2023 to 2030, Markets and Markets estimates the eVTOL market could expand at a stunning compound annual growth rate (CAGR) of 52%.

Image source: Archer Aviation.

But today, all of those SPAC-backed eVTOL stocks trade far below their all-time highs. The market's enthusiasm fizzled out as these companies struggled with delays, missed their own delivery estimates, and racked up steep losses. Rising interest rates also curbed the market's appetite for speculative pre-revenue companies.

However, as the macro environment warms up and interest rates decline, investors might want to revisit the nascent eVTOL sector. I believe one of those leading stocks -- Archer Aviation (ACHR 0.72%) -- has the potential to turn a modest $2,000 investment into tens of thousands of dollars over the next decade.

What sets Archer Aviation apart from the competition?

Archer's Midnight eVTOL aircraft can travel up to 100 miles at 150 miles per hour on a single charge. It can carry a single pilot and four passengers. Joby Aviation (JOBY -3.20%) and EHang are developing similar eVTOL aircraft, but Archer has signed a wider range of deals than most of its industry peers.

In 2021, United Airlines placed a $1 billion order for 200 of its Midnight aircraft. In 2022, it put down a $10 million deposit for those first 100 aircraft. In 2023, automaker Stellantis made a big investment in Archer and selected it as the exclusive contract manufacturer for its own eVTOL aircraft.

Archer has also been working for the U.S. Department of Defense (DOD) since 2021, and it expanded that partnership with additional contracts worth up to $142 million in 2023. It delivered its first aircraft to the U.S. Air Force last August.

Last November, Soracle -- a new joint venture formed by Japan Airlines and Sumimoto -- placed a $500 million order for 100 Midnight aircraft.

All of these budding deals could help Archer Aviation outlast many of its smaller competitors.

But why is Archer the best eVTOL stock to buy?

Archer's closest competitor, Joby Aviation, is also making plenty of progress. It attracted big investments from Toyota and Delta, it holds a long-term contract with the DOD, and it delivered its first aircraft to the U.S. Air Force in September 2023. However, four things arguably make Archer a better buy than Joby.

First, Archer has a clearer roadmap for its long-term growth. It believes it can ramp up its annual production to 10 aircraft in 2025, 48 aircraft in 2026, 252 aircraft in 2027, and 650 aircraft in 2028. It also plans to establish dedicated eVTOL air taxi routes over the next few years. Joby hasn't provided such specific production targets yet.

Second, Archer is expected to grow at a faster rate than Joby. By 2026, analysts expect Archer and Joby to generate $185 million and $98 million in revenues, respectively. We should take those estimates with a grain of salt, but Archer's growing list of partnerships and its support from Stellantis -- which has already invested hundreds of millions of dollars into the company -- could help it achieve that growth trajectory.

Third, Archer looks cheaper than Joby. With an enterprise value of $3.5 billion, it's valued at 19 times its projected sales for 2026. Joby, which has an enterprise value of $5.9 billion, trades at a whopping 60 times its projected sales for 2026. It doesn't make much sense for the slower-growing company to be trading at a higher valuation.

Lastly, Archer's insiders are net buyers, and Joby's insiders are net sellers. Over the past 12 months, Archer's insiders bought 12 times as many shares as they sold, but Joby's insiders sold nearly twice as many shares as they bought. That warmer insider sentiment suggests that Archer has more upside potential than Joby.

Archer Aviation will likely remain a volatile stock over the next few years. But if it achieves its ambitious expansion plans, it could soar a lot higher over the next few years as fleets of eVTOL air taxis take to the skies.