ZKIN vs PESI vs CWST vs CODA vs CLH

For growth investors, Coda Octopus Group, Inc.

(CODA) is the stronger pick with 30. 7% revenue growth year-over-year, versus -34. 2% for ZK International Group Co. , Ltd. (ZKIN). Coda Octopus Group, Inc. (CODA) offers the better valuation at 32. 2x trailing P/E (22. 5x forward), making it the more compelling value choice. Analysts rate Casella Waste Systems, Inc. (CWST) a "Buy" — based on 19 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, Coda Octopus Group, Inc.

(CODA) is the cheapest at 32. 2x versus Casella Waste Systems, Inc. at 712. 1x. On forward P/E, Coda Octopus Group, Inc. is actually cheaper at 22. 5x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Clean Harbors, Inc. wins at 1. 36x versus Coda Octopus Group, Inc. 's 5. 24x — a reasonable growth-adjusted valuation.

Over the past 5 years, Clean Harbors, Inc.

(CLH) delivered a total return of +198. 8%, compared to -96. 2% for ZK International Group Co. , Ltd. (ZKIN). Over 10 years, the gap is even starker: CWST returned +1059% versus ZKIN's -97. 5%. 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), ZK International Group Co.

, Ltd. (ZKIN) is the lower-risk stock at -0. 53β versus Perma-Fix Environmental Services, Inc. 's 1. 85β — meaning PESI is approximately -446% more volatile than ZKIN relative to the S&P 500. On balance sheet safety, Coda Octopus Group, Inc. (CODA) carries a lower debt/equity ratio of 1% versus 126% for Clean Harbors, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Coda Octopus Group, Inc.

(CODA) is pulling ahead at 30. 7% versus -34. 2% for ZK International Group Co. , Ltd. (ZKIN). On earnings-per-share growth, the picture is similar: Perma-Fix Environmental Services, Inc. grew EPS 43. 6% year-over-year, compared to -47. 8% for Casella Waste Systems, Inc.. Over a 3-year CAGR, CWST leads at 19. 2% 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.

Coda Octopus Group, Inc.

(CODA) is the more profitable company, earning 15. 5% net margin versus -22. 3% for Perma-Fix Environmental Services, Inc. — meaning it keeps 15. 5% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: CODA leads at 17. 1% versus -19. 0% for PESI. At the gross margin level — before operating expenses — CODA leads at 66. 5%, 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.

The PEG ratio (forward P/E divided by expected earnings growth rate) is the most precise measure of undervaluation relative to growth potential.

By this metric, Clean Harbors, Inc. (CLH) is the more undervalued stock at a PEG of 1. 36x versus Coda Octopus Group, Inc. 's 5. 24x. A PEG below 1. 5 suggests fair-to-attractive pricing relative to expected growth. On forward earnings alone, Coda Octopus Group, Inc. (CODA) trades at 22. 5x forward P/E versus 63. 9x for Casella Waste Systems, Inc. — 41. 5x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for PESI: 61. 1% to $18. 00.

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, Casella Waste Systems, Inc.

(CWST) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0. 32), +1059% 10Y return). 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 (CWST: +1059%, 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.

These companies operate in different sectors (ZKIN (Basic Materials) and PESI (Industrials) and CWST (Industrials) and CODA (Industrials) and CLH (Industrials)), which means they face different economic cycles, regulatory environments, and macro sensitivities — making direct comparison nuanced.

In terms of investment character: ZKIN is a small-cap quality compounder stock; PESI is a small-cap quality compounder stock; CWST is a small-cap high-growth stock; CODA is a small-cap high-growth stock; CLH is a mid-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.