Firefly Aerospace vs. Rocket Lab: Which Space Stock Is a Better Buy in 2026?

Sara Appino, The Motley Fool

Mon, September 21, 2026 at 9:49 PM GMT+3 5 min read

As the private space economy accelerates, investors are increasingly looking toward smaller, agile companies to capture growth. The choice between Firefly Aerospace (NASDAQ:FLY) and Rocket Lab (NASDAQ:RKLB) requires balancing high-growth potential against operational risks.

Firefly focuses on modular space systems and lunar delivery for government and commercial clients. Rocket Lab offers end-to-end solutions, including launch services and satellite manufacturing. Both companies are navigating the complex requirements of high-tech manufacturing while striving to achieve consistent profitability in a demanding environment.

The case for Firefly Aerospace

Firefly Aerospace sells launch services and lunar delivery systems to government and commercial partners. The company operates in the competitive landscape of defense stocks, where precision and reliability are essential. Its key customers include NASA, Lockheed Martin (NYSE:LMT), and Northrop Grumman (NYSE:NOC).

In FY 2025, revenue reached nearly $159.9 million, which represented a substantial 163% increase compared to the previous year. Despite this growth, the company reported a net loss of close to $298.3 million for the same period. This indicates that while sales are expanding rapidly, the costs of scaling technology remain high.

As of its December 2025 balance sheet, the debt-to-equity ratio was approximately 0.3x. This metric compares total debt to shareholder equity to help you understand how much the company relies on borrowing. Free cash flow, which is cash from operations minus capital expenditures, was negative $237.8 million for the fiscal year.

The case for Rocket Lab

Rocket Lab operates as an end-to-end space company, offering everything from rocket launches to satellite components. Its Electron rocket has established a frequent launch cadence for both civil and defense markets. Major customers include NASA, Iridium Communications (NASDAQ:IRDM), Canon (OTC:CAJFF), and Synspective (OTC:SYSPF).

In FY 2025, revenue grew roughly 38% to reach nearly $601.8 million. The company reported a net loss of approximately $198.2 million, which resulted in a net margin of negative 32.9%. Net margin describes how much profit a company generates as a percentage of its total revenue.

As of the December 2025 balance sheet, its debt-to-equity ratio was approximately 0.1x. A current ratio of 4.1x indicates the company has more than four times the assets needed to cover short-term liabilities. Free cash flow for the year was negative $321.8 million as it invested in new vehicle development.

Risk profile comparison

Firefly Aerospace faces risks from heavy revenue concentration with U.S. government contracts and potential shifts in federal funding. Technological risks are also prominent, as development delays or test stand incidents can adversely affect financial results. Furthermore, the company must effectively integrate its acquisition of SciTec to realize expected synergies in its software business.

Rocket Lab carries risks of operational failure, as it relies heavily on the continued success of its Electron vehicle. The company is also highly dependent on the leadership of its CEO, Sir Peter Beck. Additionally, Rocket Lab maintains significant indebtedness following the Iridium acquisition, and it faces competition from larger incumbents like Boeing (NYSE:BA).

Valuation comparison

Firefly Aerospace appears more attractively priced based on its P/S ratio. It does not have a forward P/E ratio because it is not expected to report a net profit in its upcoming fiscal year.

Valuation metrics sourced from Financial Modeling Prep (FMP) and may differ from other data providers.

Which stock would I buy in 2026?

I'd go with Rocket Lab, and the commercial momentum behind it makes this a straightforward call. The backlog just crossed $2 billion, launches keep increasing, and revenue is growing faster than most aerospace companies manage at this stage. The Neutron rocket program adds a growth engine that could dramatically expand its addressable market in the years ahead.

Firefly, to its credit, is making solid progress. Government defense contracts add credibility to the company, and the lunar lander program puts it at the center of NASA's commercial exploration ambitions. But commercial scale is still years away.

Rocket Lab does carry a high valuation relative to its current earnings, a signal that investors are paying today for what they expect the company to become, not what it is generating right now. That kind of premium demands consistent execution, but so far Rocket Lab has delivered. For investors comfortable with that trade-off, Rocket Lab is the stronger pick in the emerging space economy.

Should you buy stock in Firefly Aerospace right now?

Before you buy stock in Firefly Aerospace, consider this:

The Motley Fool Stock Advisor analyst team just identified what they believe are the 10 best stocks for investors to buy now… and Firefly Aerospace wasn't one of them. The 10 stocks that made the cut are built for long-term growth and could produce monster returns in the coming years.

Consider when Netflix made this list on December 17, 2004... if you invested $1,000 at the time of our recommendation, you'd have $387,158!* Or when Nvidia made this list on April 15, 2005... if you invested $1,000 at the time of our recommendation, you'd have $1,365,749!*

That performance is why people listen. With a track record of beating the S&P 500 by 4x, Stock Advisor offers a distinct advantage. Don't miss the latest top 10 list, available with Stock Advisor, and join an investing community built for the long haul.

See the 10 stocks »

*Stock Advisor returns as of September 21, 2026.

Sara Appino has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Boeing, Firefly Aerospace, Lockheed Martin, and Rocket Lab. The Motley Fool has a disclosure policy.

Firefly Aerospace vs. Rocket Lab: Which Space Stock Is a Better Buy in 2026? was originally published by The Motley Fool