AEHR vs ACLS vs ONTO vs COHU

For growth investors, Cohu, Inc.

(COHU) is the stronger pick with 12. 7% revenue growth year-over-year, versus -17. 6% for Axcelis Technologies, Inc. (ACLS). Axcelis Technologies, Inc. (ACLS) offers the better valuation at 41. 8x trailing P/E (43. 5x forward), making it the more compelling value choice. Analysts rate Axcelis Technologies, Inc. (ACLS) a "Buy" — based on 12 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, Axcelis Technologies, Inc.

(ACLS) is the cheapest at 41. 8x versus Onto Innovation Inc. at 98. 6x. On forward P/E, Onto Innovation Inc. is actually cheaper at 38. 7x — notably different from the trailing picture, reflecting expected earnings growth. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Onto Innovation Inc. wins at 1. 12x versus Axcelis Technologies, Inc. 's 2. 06x — a reasonable growth-adjusted valuation.

Over the past 5 years, Aehr Test Systems (AEHR) delivered a total return of +38.

9%, compared to +22. 2% for Cohu, Inc. (COHU). Over 10 years, the gap is even starker: AEHR returned +70. 3% versus COHU's +330. 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), Axcelis Technologies, Inc.

(ACLS) is the lower-risk stock at 2. 00β versus Aehr Test Systems's 4. 77β — meaning AEHR is approximately 139% more volatile than ACLS relative to the S&P 500. On balance sheet safety, Onto Innovation Inc. (ONTO) carries a lower debt/equity ratio of 1% versus 46% for Cohu, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Cohu, Inc.

(COHU) is pulling ahead at 12. 7% versus -17. 6% for Axcelis Technologies, Inc. (ACLS). On earnings-per-share growth, the picture is similar: Aehr Test Systems grew EPS 0. 0% year-over-year, compared to -38. 2% for Axcelis Technologies, Inc.. Over a 3-year CAGR, AEHR leads at 5. 1% 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.

Axcelis Technologies, Inc.

(ACLS) is the more profitable company, earning 14. 3% net margin versus -16. 4% for Cohu, Inc. — meaning it keeps 14. 3% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: ACLS leads at 14. 2% versus -13. 3% for COHU. At the gross margin level — before operating expenses — ONTO leads at 49. 7%, 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, Onto Innovation Inc. (ONTO) is the more undervalued stock at a PEG of 1. 12x versus Axcelis Technologies, Inc. 's 2. 06x. A PEG below 1. 5 suggests fair-to-attractive pricing relative to expected growth. On forward earnings alone, Onto Innovation Inc. (ONTO) trades at 38. 7x forward P/E versus 89. 2x for Cohu, Inc. — 50. 5x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for ONTO: 12. 5% to $308. 33.

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, Axcelis Technologies, Inc.

(ACLS) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (+1506% 10Y return). Aehr Test Systems (AEHR) carries a higher beta of 4. 77 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (ACLS: +1506%, AEHR: +70. 3%), 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 Technology sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.

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.