RGEN vs TMO

For growth investors, Repligen Corporation (RGEN) is the stronger pick with 16.

4% revenue growth year-over-year, versus 3. 9% for Thermo Fisher Scientific Inc. (TMO). Thermo Fisher Scientific Inc. (TMO) offers the better valuation at 26. 7x trailing P/E (19. 0x forward), making it the more compelling value choice. Analysts rate Repligen Corporation (RGEN) a "Buy" — based on 23 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, Thermo Fisher Scientific Inc.

(TMO) is the cheapest at 26. 7x versus Repligen Corporation at 146. 2x. On forward P/E, Thermo Fisher Scientific Inc. is actually cheaper at 19. 0x.

Over the past 5 years, Thermo Fisher Scientific Inc.

(TMO) delivered a total return of +2. 1%, compared to -32. 1% for Repligen Corporation (RGEN). Over 10 years, the gap is even starker: RGEN returned +379. 1% versus TMO's +229. 1%. 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), Thermo Fisher Scientific Inc.

(TMO) is the lower-risk stock at 1. 10β versus Repligen Corporation's 1. 76β — meaning RGEN is approximately 60% more volatile than TMO relative to the S&P 500. On balance sheet safety, Repligen Corporation (RGEN) carries a lower debt/equity ratio of 33% versus 76% for Thermo Fisher Scientific Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Repligen Corporation (RGEN) is pulling ahead at 16.

4% versus 3. 9% for Thermo Fisher Scientific Inc. (TMO). On earnings-per-share growth, the picture is similar: Repligen Corporation grew EPS 287. 0% year-over-year, compared to 7. 3% for Thermo Fisher Scientific Inc.. Over a 3-year CAGR, TMO leads at -0. 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.

Thermo Fisher Scientific Inc.

(TMO) is the more profitable company, earning 15. 1% net margin versus 6. 6% for Repligen Corporation — meaning it keeps 15. 1% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: TMO leads at 18. 2% versus 8. 1% for RGEN. At the gross margin level — before operating expenses — RGEN leads at 47. 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.

On forward earnings alone, Thermo Fisher Scientific Inc.

(TMO) trades at 19. 0x forward P/E versus 63. 9x for Repligen Corporation — 44. 9x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for TMO: 38. 4% to $654. 67.

In this comparison, TMO (0.

4% yield) pays a dividend. RGEN does not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, Thermo Fisher Scientific Inc.

(TMO) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 1. 10), +229. 1% 10Y return). Repligen Corporation (RGEN) carries a higher beta of 1. 76 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (TMO: +229. 1%, RGEN: +379. 1%), 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: RGEN is a small-cap high-growth stock; TMO 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.