Spero Therapeutics price to book ratio SPRO

Market value divided by the book value of the company's net assets, since 2018.

Today, Oct 23, 2026: 1.5×
9-year median: 2.1×
Against its 9-year history: 32nd; percentile: 0 is its lowest day, 100 its highest
9-year range: 0.4× to 6.8×
Peer median: 1.6×

Spero Therapeutics' price to book ratio is 1.5× as of Oct 23, 2026.

That is below its 9-year median of 2.1×, lower than on 68% of days in the last 9 years.

Over that time it ranged from 0.4× in Jul 2022 to 6.8× in Sep 2021.

The median for 8 large drugmakers of a similar size is 1.6×.

Price to book ratio over time

Open the interactive chart, with overlays and comparisons

Year by year

Year	End of year	Low	High
2026 so far	1.5×	1.3×	5.5×
2025	4.9×	0.6×	5.1×
2024	0.9×	0.7×	1.7×
2023	1.5×	1.0×	3.2×
2022	2.8×	0.4×	3.8×
2021	4.6×	2.9×	6.8×
2020	4.0×	1.3×	4.5×
2019	2.2×	1.0×	2.5×
2018	1.0×	0.9×	3.3×

Against its peers

Companies in Drug Manufacturers - General nearest Spero Therapeutics' size, closest first, today.

Company	Price to book ratio
SPROSpero Therapeutics	1.5×
LFVNLifevantage	2.2×
ATNMActinium Pharmaceuticals	1.6×
NATRNatures Sunshine Products	1.3×
ARVNArvinas	0.8×
PBYIPuma Biotechnology	4.1×
IRWDIronwood Pharmaceuticals	n/m
ZVRAZevra Therapeutics	2.7×
CRMDCorMedix	1.3×
Peer median	1.6×

What the price to book ratio tells you

Market value divided by the accounting value of the company's net assets. Below 1 means the market values the business at less than what it owns on paper.

Book value misses brands, software and people, so asset-light companies always look expensive on it. Most useful for banks and industrials.

More on Spero Therapeutics

Valuation data, not investment advice. Prices as of Oct 23, 2026. Reported figures come from the company's filings with the SEC.