QSI vs PACB vs CDNA vs ILMN vs ACMR

For growth investors, ACM Research, Inc.

(ACMR) is the stronger pick with 15. 2% revenue growth year-over-year, versus -20. 3% for Quantum-Si incorporated (QSI). Illumina, Inc. (ILMN) offers the better valuation at 25. 5x trailing P/E (27. 2x forward), making it the more compelling value choice. Analysts rate Quantum-Si incorporated (QSI) 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.

On trailing P/E, Illumina, Inc.

(ILMN) is the cheapest at 25. 5x versus ACM Research, Inc. at 43. 2x. On forward P/E, CareDx, Inc is actually cheaper at 23. 3x — 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: ACM Research, Inc. wins at 0. 87x versus Illumina, Inc. 's 6. 43x — a PEG below 1. 0 traditionally signals the market is underpricing earnings growth.

Over the past 5 years, ACM Research, Inc.

(ACMR) delivered a total return of +133. 4%, compared to -93. 4% for Pacific Biosciences of California, Inc. (PACB). Over 10 years, the gap is even starker: ACMR returned +31. 0% versus QSI's -90. 8%. 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), Illumina, Inc.

(ILMN) is the lower-risk stock at 1. 20β versus Quantum-Si incorporated's 3. 69β — meaning QSI is approximately 206% more volatile than ILMN relative to the S&P 500. On balance sheet safety, Quantum-Si incorporated (QSI) carries a lower debt/equity ratio of 2% versus 142% for Pacific Biosciences of California, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), ACM Research, Inc.

(ACMR) is pulling ahead at 15. 2% versus -20. 3% for Quantum-Si incorporated (QSI). On earnings-per-share growth, the picture is similar: Illumina, Inc. grew EPS 170. 9% year-over-year, compared to -143. 0% for CareDx, Inc. Over a 3-year CAGR, ACMR leads at 32. 3% 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.

Illumina, Inc.

(ILMN) is the more profitable company, earning 19. 6% net margin versus -41. 6% for Quantum-Si incorporated — meaning it keeps 19. 6% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: ILMN leads at 19. 9% versus -39. 8% for QSI. At the gross margin level — before operating expenses — CDNA leads at 67. 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.

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, ACM Research, Inc. (ACMR) is the more undervalued stock at a PEG of 0. 87x versus Illumina, Inc. 's 6. 43x. A PEG below 1. 0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, CareDx, Inc (CDNA) trades at 23. 3x forward P/E versus 30. 8x for ACM Research, Inc. — 7. 6x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for ACMR: 26. 7% to $75. 00.

In this comparison, ACMR (0.

2% yield) pays a dividend. QSI, PACB, CDNA, ILMN do not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, CareDx, Inc (CDNA) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (+393.

7% 10Y return). Quantum-Si incorporated (QSI) carries a higher beta of 3. 69 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (CDNA: +393. 7%, QSI: -90. 8%), 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 (QSI (Healthcare) and PACB (Healthcare) and CDNA (Healthcare) and ILMN (Healthcare) and ACMR (Technology)), which means they face different economic cycles, regulatory environments, and macro sensitivities — making direct comparison nuanced.

In terms of investment character: QSI is a small-cap quality compounder stock; PACB is a small-cap quality compounder stock; CDNA is a small-cap quality compounder stock; ILMN is a mid-cap quality compounder stock; ACMR is a small-cap high-growth 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.