The Market Didn't See Rocket Lab's Move Coming. These 2 Stocks Are Next to Watch.

Many investors shunned Rocket Lab (NASDAQ: RKLB), a developer of reusable orbital rockets, when it went public via a merger with a special-purpose acquisition company (SPAC) in August 2021. It started trading at $11.58, but sank to a record low of $3.79 in June 2022.

But today, Rocket Lab's stock trades at about $82. It skyrocketed after successfully launching its Electron rocket, which can carry small payloads of up to 300 kilograms into space, 87 times. It secured contracts with big customers, including NASA, the U.S. Space Force, the Swedish National Space Agency, Capella Space, Kinéis, and BlackSky Technology. It plans to launch the Neutron, a higher-capacity rocket, by the end of this year.

Image source: Getty Images.

From 2025 to 2028, analysts expect Rocket Lab's revenue to surge from $602 million to $1.56 billion as it launches more rockets and gains more contracts. That's an impressive growth trajectory, but this space stock isn't cheap at 29 times its 2028 sales. So instead of chasing Rocket Lab, investors should focus on two other promising stocks that are still trading far below their all-time highs: QuantumScape (NASDAQ: QS) and Plug Power (NASDAQ: PLUG).

QuantumScape

QuantumScape develops solid-state lithium-metal batteries that offer better thermal stability, higher charging capacities, and shorter charging times than conventional lithium-ion batteries. It's been co-developing those batteries with Volkswagen (OTC:VWAP.Y) for over a decade.

QuantumScape's QSE-5 batteries for electric vehicles (EVs) have an energy density of 844 Wh/L (watt hours per liter) and can be rapidly charged from 10% to 80% in under 15 minutes. For reference, most lithium-ion batteries for EVs only have an average energy density of 300-700 Wh/L with a fast-charging time of 20 minutes to an hour.

QuantumScape hasn't commercialized any of its batteries yet, and it's only delivered samples to Volkswagen and other automakers. However, its recent "Cobra" upgrade to its separator process should significantly boost its yields and sample shipments this year.

It plans to license its first commercial designs by the end of 2026. Assuming it sticks to that plan and licenses its technology to more automakers, analysts expect its revenue to surge from nothing this year to $63 million in 2027 and $99 million in 2028. It isn't cheap at 45 times its 2028 sales, but it could grow much larger if its solid-state batteries replace lithium-ion batteries.

Plug Power

Plug Power sells hydrogen fuel cells, charging systems, electrolyzers, and storage equipment. Two of its largest customers are Amazon and Walmart, which use its fuel cells and charging systems to power their hydrogen-powered forklifts. It's also selling more electrolyzer systems for green hydrogen production.

By the end of 2025, Plug Power had deployed more than 74,000 fuel cell systems worldwide, up from roughly 50,000 systems at the end of 2021. It suffered a severe slowdown in 2024 as it lapped two major acquisitions and faced tougher macro headwinds, but its revenue rose again in 2025 as it narrowed its net loss.

From 2025 to 2028, analysts expect Plug's revenue to grow at a 17% CAGR from $710 million to $1.15 billion. They also expect its adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) to turn positive by the final year.

Plug Power's stock still looks reasonably valued at six times this year's sales, and it could have plenty of room to grow as the hydrogen market expands. It's already producing more green hydrogen in Texas and Georgia -- and building a new hydrogen liquefaction plant in Louisiana through a joint venture with Olin -- to meet the market's rising demand. Therefore, this stock could soar a lot higher once the hydrogen market attracts more attention.

Leo Sun has positions in Amazon. The Motley Fool has positions in and recommends Amazon, BlackSky Technology, Rocket Lab, and Walmart. The Motley Fool has a disclosure policy.