SPRO

MKT CAP:$161M

Spero Therapeutics, Inc.

Market Cap

$161M

Healthcare·Biotechnology·🇺🇸 United States·NASDAQ

Healthcare·Biotechnology·🇺🇸·NASDAQ

Stock Price

$2.80+$0.45 (+19.15%)

Apr 23, 2026

Company Details

Spero Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on identifying, developing, and commercializing treatments for multi-drug resistant (MDR) bacterial infections and rare diseases in the United States. The company...

CEO

Esther Rajavelu

IPO Date

Nov 2, 2017

Website

sperotherapeutics.com

Key Metrics TTM

Revenue

$60M

+40.7% YoY

Net Income

$9M

EPS (Diluted)

$0.12

Free Cash Flow

-$13M

Revenue / Share

$1.02

Gross Margin

77.5%

Operating Margin

-0.0%

Net Margin

14.2%

FCF Margin

-20.9%

P/S

2.7x

P/E

18.8x

Earnings Reports

Q1 2026

May 13, 2026

PENDING

FY 2025

Mar 26, 2026

$60M+24.3%EPS $0.15

Q4 2025

Mar 26, 2026

$40M+163.6%EPS $0.53

Q3 2025

Nov 13, 2025

$3M-77.4%EPS -$0.13

Q2 2025

Aug 12, 2025

$12M+15.7%EPS -$0.03

Revenue & Profitability

Quarter	Revenue	Gross Profit	Operating Income
Q1 22	$247.0K	$247.0K	-$30M
Q2 22	$896.0K	$896.0K	-$26M
Q3 22	$1M	$1M	-$12M
Q4 22	$46M	$46M	$26M
Q1 23	$2M	-$7M	-$14M
Q2 23	$3M	-$7M	-$13M
Q3 23	$25M	$25M	-$2M
Q4 23	$74M	$24M	$51M
Q1 24	$4M	$4M	-$14M
Q2 24	$10M	-$14M	-$19M
Q3 24	$13M	$13M	-$19M
Q4 24	$15M	-$80M	-$22M
Q1 25	$6M	-$8M	-$15M
Q2 25	$12M	$12M	-$2M
Q3 25	$3M	$3M	-$8M
Q4 25	$40M	$40M	$25M

Valuation

Quarter	P/S	P/E
Q1 22	44.1x	—
Q2 22	6.7x	—
Q3 22	19.8x	—
Q4 22	2.0x	—
Q1 23	1.6x	—
Q2 23	1.5x	—
Q3 23	0.8x	—
Q4 23	0.7x	3.3x
Q1 24	0.9x	4.1x
Q2 24	0.6x	3.9x
Q3 24	0.7x	20.6x
Q4 24	1.3x	—
Q1 25	0.9x	—
Q2 25	3.5x	—
Q3 25	3.0x	—
Q4 25	2.1x	15.1x

Operating Cash Flow

Quarter	Operating CF	Free CF
Q1 22	-$28M	-$28M
Q2 22	-$23M	-$23M
Q3 22	-$957.0K	-$957.0K
Q4 22	$44M	$44M
Q1 23	-$13M	-$13M
Q2 23	-$19M	-$19M
Q3 23	$16M	$16M
Q4 23	-$17M	-$17M
Q1 24	$6M	$6M
Q2 24	-$19M	-$19M
Q3 24	$13M	$13M
Q4 24	-$23M	-$23M
Q1 25	-$4M	-$4M
Q2 25	-$18M	-$18M
Q3 25	$17M	$17M
Q4 25	-$8M	-$8M

Capital Expenditures

Quarter	CapEx
Q1 22	$0
Q2 22	$0
Q3 22	$0
Q4 22	$129.0K
Q1 23	$0
Q2 23	$0
Q3 23	$0
Q4 23	$0
Q1 24	$0
Q2 24	$0
Q3 24	$0
Q4 24	$0
Q1 25	$0
Q2 25	$0
Q3 25	$0
Q4 25	$0

CapEx

OpEx vs Revenue Growth (YoY)

Quarter	Revenue Growth	OpEx Growth
Q1 22	-96.6%	+14.0%
Q2 22	-57.5%	+30.6%
Q3 22	+52.8%	-44.4%
Q4 22	+1589.3%	-32.5%
Q1 23	+737.7%	-46.5%
Q2 23	+203.1%	-42.1%
Q3 23	+2254.3%	+112.2%
Q4 23	+58.6%	+12.5%
Q1 24	+103.2%	+11.6%
Q2 24	+275.4%	+87.5%
Q3 24	-47.1%	+17.0%
Q4 24	-79.5%	+59.9%
Q1 25	+39.7%	+13.3%
Q2 25	+15.7%	-51.3%
Q3 25	-77.4%	-65.8%
Q4 25	+163.6%	-60.3%

Stock-Based Compensation

Quarter	SBC ($)	% of Revenue
Q1 22	$3M	1296.8%
Q2 22	$0	0.0%
Q3 22	$2M	194.6%
Q4 22	$2M	5.4%
Q1 23	$2M	104.9%
Q2 23	$2M	68.4%
Q3 23	$2M	7.5%
Q4 23	$2M	2.7%
Q1 24	$2M	48.1%
Q2 24	$2M	20.7%
Q3 24	$2M	16.0%
Q4 24	$2M	10.0%
Q1 25	$2M	26.5%
Q2 25	$714.0K	6.0%
Q3 25	$1M	34.4%
Q4 25	$1M	2.5%

OpEx Breakdown

Quarter	R&D	G&A	S&M
Q1 22	$17M	$15M	—
Q2 22	$8M	$8M	—
Q3 22	$7M	$7M	—
Q4 22	$15M	$6M	—
Q1 23	$9M	$7M	—
Q2 23	$10M	$6M	—
Q3 23	$16M	$6M	—
Q4 23	$17M	$6M	$566.0K
Q1 24	$17M	$6M	—
Q2 24	$24M	$6M	—
Q3 24	$27M	$5M	—
Q4 24	$29M	$6M	$792.0K
Q1 25	$14M	$7M	—
Q2 25	$11M	$6M	—
Q3 25	$9M	$4M	—
Q4 25	$6M	$4M	—

Revenue Segments

Quarter	Collaboration Revenue	Collaboration Revenue Related Party	Grant Revenue
Q1 25	$12.0K	$5M	$763.0K
Q4 25	$13M	$27M	$2M

War Chest

Quarter	Cash	Short-term Investments	Total
Q1 22	$72M	$50M	$122M
Q2 22	$45M	$0	$45M
Q3 22	$50M	$0	$50M
Q4 22	$109M	$0	$109M
Q1 23	$96M	$0	$96M
Q2 23	$78M	$0	$78M
Q3 23	$94M	$0	$94M
Q4 23	$76M	$0	$76M
Q1 24	$82M	$0	$82M
Q2 24	$64M	$0	$64M
Q3 24	$76M	$0	$76M
Q4 24	$53M	$0	$53M
Q1 25	$49M	$0	$49M
Q2 25	$31M	$0	$31M
Q3 25	$49M	$0	$49M
Q4 25	$40M	$0	$40M

Shares Outstanding

Quarter	Shares (Diluted)	QoQ Change	YoY Change
Q1 22	33M	+1.5%	+10.9%
Q2 22	33M	+1.1%	+11.1%
Q3 22	36M	+8.8%	+11.7%
Q4 22	49M	+35.8%	+51.6%
Q1 23	53M	+7.8%	+61.1%
Q2 23	53M	+0.1%	+59.4%
Q3 23	53M	+0.3%	+46.9%
Q4 23	53M	+0.8%	+9.0%
Q1 24	54M	+0.8%	+1.9%
Q2 24	54M	+0.8%	+2.6%
Q3 24	54M	+0.3%	+2.7%
Q4 24	54M	-0.2%	+1.8%
Q1 25	55M	+2.5%	+3.5%
Q2 25	56M	+1.2%	+3.8%
Q3 25	56M	+0.5%	+4.0%
Q4 25	59M	+5.5%	+9.9%

Shares Outstanding

Revenue Per Employee

Period	Revenue/Employee	Employees
Q1 22	$1.7K	146
Q2 22	$6.1K	146
Q3 22	$7.4K	146
Q4 22	$1M	35
Q1 23	$59.1K	35
Q2 23	$77.6K	35
Q3 23	$727.8K	35
Q4 23	$2M	46
Q1 24	$91.4K	46
Q2 24	$221.7K	46
Q3 24	$292.8K	46
Q4 24	$470.1K	32
Q1 25	$183.6K	32
Q2 25	$368.8K	32
Q3 25	$95.3K	32
Q4 25	$198	200K

Revenue / Employee