NPWR vs SPIR vs ASTS vs CLNE

For growth investors, AST SpaceMobile, Inc.

(ASTS) is the stronger pick with 1505% revenue growth year-over-year, versus -100. 0% for NET Power Inc. (NPWR). Spire Global, Inc. (SPIR) offers the better valuation at 10. 0x trailing P/E, making it the more compelling value choice. Analysts rate NET Power Inc. (NPWR) a "Buy" — based on 2 analyst ratings — the highest consensus in this comparison. The "better buy" depends entirely on your goals: growth investors should weight revenue trajectory, value investors should weight P/E and PEG, and income investors should weight dividend yield and streak.

Over the past 5 years, AST SpaceMobile, Inc.

(ASTS) delivered a total return of +688. 2%, compared to -79. 6% for Spire Global, Inc. (SPIR). Over 10 years, the gap is even starker: ASTS returned +568. 8% versus NPWR's -79. 2%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.

By beta (market sensitivity over 5 years), Clean Energy Fuels Corp.

(CLNE) is the lower-risk stock at 1. 19β versus NET Power Inc. 's 3. 18β — meaning NPWR is approximately 167% more volatile than CLNE relative to the S&P 500. On balance sheet safety, NET Power Inc. (NPWR) carries a lower debt/equity ratio of 1% versus 18% for Clean Energy Fuels Corp. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), AST SpaceMobile, Inc.

(ASTS) is pulling ahead at 1505% versus -100. 0% for NET Power Inc. (NPWR). On earnings-per-share growth, the picture is similar: Spire Global, Inc. grew EPS 137. 8% year-over-year, compared to -995. 5% for NET Power Inc.. Over a 3-year CAGR, ASTS leads at 72. 5% annualised revenue growth. Higher growth typically commands a higher valuation multiple — check whether the premium P/E or P/S is justified by the growth rate using the PEG ratio.

Spire Global, Inc.

(SPIR) is the more profitable company, earning 71. 7% net margin versus -482. 2% for AST SpaceMobile, Inc. — meaning it keeps 71. 7% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: NPWR leads at 0. 0% versus -405. 7% for ASTS. At the gross margin level — before operating expenses — ASTS leads at 53. 4%, reflecting greater pricing power or product mix advantage. Stronger margins indicate durable pricing power, lower cost of revenue, or higher mix of software/services. They are one of the clearest signs of business quality.

None of the stocks in this comparison currently pay a material dividend.

All are effectively zero-yield and should be held for capital appreciation rather than income.

For long-horizon retirement investors, Clean Energy Fuels Corp.

(CLNE) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 1. 19)). NET Power Inc. (NPWR) carries a higher beta of 3. 18 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (CLNE: -26. 9%, NPWR: -79. 2%), confirming both are viable long-term holds — but the lower-volatility option typically results in less emotional selling during corrections. Retirement portfolios generally favour predictability over maximum returns. Consult a financial advisor before making allocation decisions.

These companies operate in different sectors (NPWR (Industrials) and SPIR (Industrials) and ASTS (Technology) and CLNE (Energy)), which means they face different economic cycles, regulatory environments, and macro sensitivities — making direct comparison nuanced.

In terms of investment character: NPWR is a small-cap quality compounder stock; SPIR is a large-cap deep-value stock; ASTS is a mid-cap high-growth stock; CLNE is a small-cap quality compounder stock. These fundamental differences mean investors should not choose between them on a single metric — the "better stock" depends entirely on which of these characteristics aligns with your investment strategy.