SPRO vs TBPH

For growth investors, Theravance Biopharma, Inc.

(TBPH) is the stronger pick with 12. 1% revenue growth year-over-year, versus -53. 8% for Spero Therapeutics, Inc. (SPRO). Analysts rate Spero Therapeutics, Inc. (SPRO) a "Buy" — based on 13 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.

Over the past 5 years, Theravance Biopharma, Inc.

(TBPH) delivered a total return of -13. 8%, compared to -81. 3% for Spero Therapeutics, Inc. (SPRO). Over 10 years, the gap is even starker: TBPH returned -8. 6% versus SPRO's -78. 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), Theravance Biopharma, Inc.

(TBPH) is the lower-risk stock at 0. 89β versus Spero Therapeutics, Inc. 's 0. 90β — meaning SPRO is approximately 1% more volatile than TBPH relative to the S&P 500. On balance sheet safety, Spero Therapeutics, Inc. (SPRO) carries a lower debt/equity ratio of 9% versus 28% for Theravance Biopharma, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Theravance Biopharma, Inc.

(TBPH) is pulling ahead at 12. 1% versus -53. 8% for Spero Therapeutics, Inc. (SPRO). On earnings-per-share growth, the picture is similar: Theravance Biopharma, Inc. grew EPS -15. 0% year-over-year, compared to -395. 3% for Spero Therapeutics, Inc.. Over a 3-year CAGR, SPRO leads at 150. 0% 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.

Theravance Biopharma, Inc.

(TBPH) is the more profitable company, earning -87. 6% net margin versus -142. 9% for Spero Therapeutics, Inc. — meaning it keeps -87. 6% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: TBPH leads at -72. 9% versus -152. 9% for SPRO. At the gross margin level — before operating expenses — TBPH leads at 100. 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.

On forward earnings alone, Spero Therapeutics, Inc.

(SPRO) trades at 3. 7x forward P/E versus 6. 7x for Theravance Biopharma, Inc. — 2. 9x cheaper on a one-year earnings basis.

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, Theravance Biopharma, Inc.

(TBPH) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0. 89)). Both have compounded well over 10 years (TBPH: -8. 6%, SPRO: -78. 2%), 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.

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.