MNTK vs OPAL vs CLNE vs GPRE

For growth investors, OPAL Fuels Inc.

(OPAL) is the stronger pick with 16. 3% revenue growth year-over-year, versus -14. 9% for Green Plains Inc. (GPRE). OPAL Fuels Inc. (OPAL) offers the better valuation at 15. 6x trailing P/E, making it the more compelling value choice. Analysts rate Clean Energy Fuels Corp. (CLNE) a "Buy" — based on 22 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.

On trailing P/E, OPAL Fuels Inc.

(OPAL) is the cheapest at 15. 6x versus Montauk Renewables, Inc. at 116. 4x. On forward P/E, Montauk Renewables, Inc. is actually cheaper at 13. 1x — notably different from the trailing picture, reflecting expected earnings growth.

Over the past 5 years, Green Plains Inc.

(GPRE) delivered a total return of -48. 5%, compared to -85. 1% for Montauk Renewables, Inc. (MNTK). Over 10 years, the gap is even starker: GPRE returned +21. 3% versus MNTK's -87. 9%. 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 Montauk Renewables, Inc. 's 1. 82β — meaning MNTK is approximately 53% more volatile than CLNE relative to the S&P 500. On balance sheet safety, Clean Energy Fuels Corp. (CLNE) carries a lower debt/equity ratio of 18% versus 73% for OPAL Fuels Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), OPAL Fuels Inc.

(OPAL) is pulling ahead at 16. 3% versus -14. 9% for Green Plains Inc. (GPRE). On earnings-per-share growth, the picture is similar: OPAL Fuels Inc. grew EPS 638. 9% year-over-year, compared to -173. 0% for Clean Energy Fuels Corp.. Over a 3-year CAGR, OPAL leads at 14. 0% 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.

OPAL Fuels Inc.

(OPAL) is the more profitable company, earning 1. 2% net margin versus -52. 3% for Clean Energy Fuels Corp. — meaning it keeps 1. 2% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: MNTK leads at 2. 3% versus -22. 1% for CLNE. At the gross margin level — before operating expenses — MNTK leads at 39. 0%, 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.

On forward earnings alone, Montauk Renewables, Inc.

(MNTK) trades at 13. 1x forward P/E versus 46. 6x for Green Plains Inc. — 33. 6x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for CLNE: 51. 5% to $3. 50.

In this comparison, OPAL (15.

3% yield) pays a dividend. MNTK, CLNE, GPRE do not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, OPAL Fuels Inc.

(OPAL) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (15. 3% yield). Montauk Renewables, Inc. (MNTK) carries a higher beta of 1. 82 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (OPAL: -76. 1%, MNTK: -87. 9%), 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 (MNTK (Utilities) and OPAL (Utilities) and CLNE (Energy) and GPRE (Basic Materials)), which means they face different economic cycles, regulatory environments, and macro sensitivities — making direct comparison nuanced.

In terms of investment character: MNTK is a small-cap quality compounder stock; OPAL is a small-cap high-growth stock; CLNE is a small-cap quality compounder stock; GPRE is a small-cap quality compounder stock. OPAL pays a dividend while MNTK, CLNE, GPRE do not, making them suitable for different income and tax situations. 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.