SERA vs PGNY vs NTRA vs ILMN

For growth investors, Natera, Inc.

(NTRA) is the stronger pick with 35. 9% revenue growth year-over-year, versus -0. 8% for Illumina, Inc. (ILMN). Illumina, Inc. (ILMN) offers the better valuation at 25. 5x trailing P/E (26. 8x forward), making it the more compelling value choice. Analysts rate Sera Prognostics, Inc. (SERA) a "Buy" — based on 5 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 Progyny, Inc. at 29. 5x. On forward P/E, Progyny, Inc. is actually cheaper at 16. 4x — 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: Progyny, Inc. wins at 2. 45x versus Illumina, Inc. 's 6. 33x.

Over the past 5 years, Natera, Inc.

(NTRA) delivered a total return of +115. 9%, compared to -83. 9% for Sera Prognostics, Inc. (SERA). Over 10 years, the gap is even starker: NTRA returned +20. 9% versus SERA's -83. 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), Progyny, Inc.

(PGNY) is the lower-risk stock at 0. 71β versus Sera Prognostics, Inc. 's 1. 56β — meaning SERA is approximately 120% more volatile than PGNY relative to the S&P 500. On balance sheet safety, Sera Prognostics, Inc. (SERA) carries a lower debt/equity ratio of 3% versus 94% for Illumina, Inc. — giving it more financial flexibility in a downturn.

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

(NTRA) is pulling ahead at 35. 9% versus -0. 8% for Illumina, Inc. (ILMN). On earnings-per-share growth, the picture is similar: Illumina, Inc. grew EPS 170. 9% year-over-year, compared to 0. 7% for Natera, Inc.. Over a 3-year CAGR, NTRA leads at 41. 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.

Illumina, Inc.

(ILMN) is the more profitable company, earning 19. 6% net margin versus -394. 2% for Sera Prognostics, Inc. — 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 -450. 7% for SERA. At the gross margin level — before operating expenses — ILMN leads at 66. 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, Progyny, Inc. (PGNY) is the more undervalued stock at a PEG of 2. 45x versus Illumina, Inc. 's 6. 33x. Both stocks trade at elevated growth-adjusted valuations, so expected growth needs to materialise. On forward earnings alone, Progyny, Inc. (PGNY) trades at 16. 4x forward P/E versus 26. 8x for Illumina, Inc. — 10. 4x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for SERA: 160. 4% to $5. 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, Progyny, Inc.

(PGNY) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0. 71)). Sera Prognostics, Inc. (SERA) carries a higher beta of 1. 56 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (PGNY: +20. 2%, SERA: -83. 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.

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

In terms of investment character: SERA is a small-cap quality compounder stock; PGNY is a small-cap quality compounder stock; NTRA is a mid-cap high-growth stock; ILMN 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.