ANTX vs SPRO

Spero Therapeutics, Inc.

(SPRO) offers the better valuation at 19. 0x trailing P/E (4. 3x forward), making it the more compelling value choice. Analysts rate AN2 Therapeutics, Inc. (ANTX) a "Buy" — based on 8 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, AN2 Therapeutics, Inc.

(ANTX) delivered a total return of -69. 2%, compared to -81. 8% for Spero Therapeutics, Inc. (SPRO). Over 10 years, the gap is even starker: ANTX returned -39. 4% versus SPRO's -75. 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), AN2 Therapeutics, Inc.

(ANTX) is the lower-risk stock at 0. 42β versus Spero Therapeutics, Inc. 's 1. 26β — meaning SPRO is approximately 199% more volatile than ANTX relative to the S&P 500.

On earnings-per-share growth, the picture is similar: Spero Therapeutics, Inc.

grew EPS 111. 8% year-over-year, compared to 32. 6% for AN2 Therapeutics, Inc.. 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.

Spero Therapeutics, Inc.

(SPRO) is the more profitable company, earning 14. 4% net margin versus 0. 0% for AN2 Therapeutics, Inc. — meaning it keeps 14. 4% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: ANTX leads at 0. 0% versus -0. 0% for SPRO. At the gross margin level — before operating expenses — SPRO 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.

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, AN2 Therapeutics, Inc.

(ANTX) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0. 42)). Both have compounded well over 10 years (ANTX: -39. 4%, SPRO: -75. 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.

In terms of investment character: ANTX is a small-cap quality compounder stock; SPRO 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.