Which has grown faster, IBIO or SPRO?

Over the past five years, SPRO grew revenue faster — IBIO at a -46.91% CAGR versus SPRO at 22.93%.

Is IBIO or SPRO more profitable?

SPRO runs the higher net margin — IBIO at -33044.00% versus SPRO at 17.18%.

How have IBIO and SPRO total returns compared?

Over the past 5 years, IBIO delivered -70.43% and SPRO delivered -42.70% annualized total return. Past performance doesn't predict future results.

iBio, Inc. (IBIO) vs Spero Therapeutics, Inc. (SPRO)

A side-by-side comparison of iBio, Inc. and Spero Therapeutics, Inc. across valuation, profitability, dividends, and growth — built entirely from reported fundamentals, as of October 6, 2026. Differences are shown without an overall score or investment verdict.

IBIO

iBio, Inc.

$68M

$1.05HealthcareDelayed quote: Oct 6, 2026, 1:25 PM EDT

SPRO

Spero Therapeutics, Inc.

$69M

$1.19HealthcareDelayed quote: Oct 6, 2026, 1:24 PM EDT

Total return — IBIO vs SPRO

growth of $100 · dividends reinvested · last 9y

IBIO -99.9% (-55.4%/yr)SPRO -89.9% (-22.5%/yr)SPRO compounded faster over this window

Log scale — wide-divergence pair

IBIO SPRO

IBIO vs SPRO: by the numbers

•SPRO is the larger company ($69M vs $68M market cap).
•SPRO is profitable (17.18% net margin) while IBIO runs a net loss (-33044.00%).
•SPRO grew revenue faster over the past five years (22.93% vs -46.91% CAGR).

Metrics side by side

Valuation

Metric	IBIO	SPRO
P/E ratio	N/A	10.77
P/S ratio	675.23	1.60
P/B ratio	0.79	1.55
EV / EBITDA	N/A	3.30
FCF yield	N/A	28.54%

Profitability

Metric	IBIO	SPRO
Gross margin	100.00%	100.00%
Operating margin	-35141.00%	-0.04%
Net margin	-33044.00%	17.18%
ROE	-38.55%	16.70%
ROIC	-40.22%	13.12%

Growth (annualized)

Metric	IBIO	SPRO
Revenue CAGR (5Y)	-46.91%	22.93%
Total return CAGR (5Y)	-70.43%	-42.70%

Frequently asked

Which has grown faster, IBIO or SPRO?: Over the past five years, SPRO grew revenue faster — IBIO at a -46.91% CAGR versus SPRO at 22.93%.
Is IBIO or SPRO more profitable?: SPRO runs the higher net margin — IBIO at -33044.00% versus SPRO at 17.18%.
How have IBIO and SPRO total returns compared?: Over the past 5 years, IBIO delivered -70.43% and SPRO delivered -42.70% annualized total return. Past performance doesn't predict future results.

Go deeper

Full IBIO analysis Full SPRO analysis Interactive comparison tool

Dig into the metrics

Spero Therapeutics P/E ratio iBio ROE Spero Therapeutics ROE iBio operating margin Spero Therapeutics operating margin iBio revenue growth Spero Therapeutics revenue growth iBio free cash flow Spero Therapeutics free cash flow

iBio & Spero Therapeutics appear in these rankings

Fastest Revenue Growth Stocks Highest FCF Yield Stocks Lowest P/E Ratio Stocks

Figures are sourced from reported fundamentals and the latest end-of-day price. This comparison is informational only and is not investment advice. Past performance does not predict future results. See our methodology. Compiled by TGMCharts Research · data verified October 6, 2026.