CLIR vs PESI

For growth investors, ClearSign Technologies Corporation (CLIR) is the stronger pick with 49.

6% revenue growth year-over-year, versus 4. 3% for Perma-Fix Environmental Services, Inc. (PESI). Analysts rate ClearSign Technologies Corporation (CLIR) a "Buy" — based on 1 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, Perma-Fix Environmental Services, Inc.

(PESI) delivered a total return of +45. 6%, compared to -89. 1% for ClearSign Technologies Corporation (CLIR). Over 10 years, the gap is even starker: PESI returned +178. 6% versus CLIR's -88. 7%. 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), ClearSign Technologies Corporation (CLIR) is the lower-risk stock at 1.

43β versus Perma-Fix Environmental Services, Inc. 's 1. 85β — meaning PESI is approximately 29% more volatile than CLIR relative to the S&P 500. On balance sheet safety, ClearSign Technologies Corporation (CLIR) carries a lower debt/equity ratio of 1% versus 9% for Perma-Fix Environmental Services, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), ClearSign Technologies Corporation (CLIR) is pulling ahead at 49.

6% versus 4. 3% for Perma-Fix Environmental Services, Inc. (PESI). On earnings-per-share growth, the picture is similar: Perma-Fix Environmental Services, Inc. grew EPS 43. 6% year-over-year, compared to 15. 4% for ClearSign Technologies Corporation. Over a 3-year CAGR, CLIR leads at 80. 9% 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.

Perma-Fix Environmental Services, Inc.

(PESI) is the more profitable company, earning -22. 3% net margin versus -147. 4% for ClearSign Technologies Corporation — meaning it keeps -22. 3% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: PESI leads at -19. 0% versus -180. 4% for CLIR. At the gross margin level — before operating expenses — CLIR leads at 31. 1%, 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, ClearSign Technologies Corporation (CLIR) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding.

Perma-Fix Environmental Services, Inc. (PESI) carries a higher beta of 1. 85 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (CLIR: -88. 7%, PESI: +178. 6%), 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.

Both stocks operate in the Industrials sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.

In terms of investment character: CLIR is a small-cap high-growth stock; PESI 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.