Spero Therapeutics, Inc.

SPRO
About the company

Spero Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on identifying and developing novel treatments for multi-drug resistant (MDR) bacterial infections and rare diseases in the United States. The company's product candidates include Tebipenem HBr (tebipenem pivoxil hydrobromide), an oral carbapenem-class antibiotic to treat complicated urinary tract infections, including pyelonephritis for adult patients, which has completed second Phase 3 trial.

Country: United StatesPrice: $1.00Market Cap: $58.3M

Investment snapshot

6%positive consensus
Scored 1d ago

Positive

1

BUY / PASS

Neutral / negative

3 / 12

NEUTRAL / FAIL

Median fair value

$2.08

+108.5% vs price

Models with upside

2 / 17

Positive margin of safety

Strongest signal

SPRO undervalued: all 2 models price fair value above $1.00 (median $2.08)

Key risk

No clean pass — all 8 investors flag at least one growth criterion

Framework analysis

VerdictMeaning
BUYPositive purchase signal: the framework's buy requirements are met.
PASSThe company clears the framework's checklist or screen, but the framework does not produce a buy signal. For valuation frameworks this often means margin of safety is missing, insufficient, or unavailable; some screen-only frameworks have no intrinsic-value BUY state.
NEUTRALNeither a positive nor negative conclusion. It does not mean to hold an existing position.
FAILThe company does not clear the framework's requirements.
RankedRanked strategies do not use PASS: selected cohort is BUY, outside the cohort is FAIL, and unranked is NEUTRAL.

Current investor scores use trailing 12-month flows and the latest balance sheet where supported. Multi-year and EPS tests retain annual history; each framework shows its financial basis below. Intrinsic values use annual financials.

MetricGraham

Defensive Value

Buffett

Quality Compounder

Lynch

GARP

Greenblatt

Magic Formula

Piotroski

F-Score

Dreman

Contrarian Value

Munger

Quality Focus

Pabrai

Dhandho Framework

Akre

Three-Legged Stool

Marks

Risk-Aware Value

Ackman

Activist Value

Templeton

Global Bargain Hunter

Sleep

Scale Economies Shared

Asness

Systematic Factors

Neff

Low-P/E Total Return

Schloss

Asset-Value Discipline

O'Shaughnessy

Systematic Factor Composite

VerdictFAILFAILFAILNot rankedPASSFAILFAILNEUTRALFAILFAILFAILFAILFAILNEUTRALFAILFAILNEUTRAL
Score
AnalysisChecking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…Checking access…
Intrinsic Value (annual)N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
Margin of Safety+46.8%N/AN/AN/AN/AN/AN/A+56.3%N/AN/AN/AN/AN/AN/AN/AN/AN/A
Financial Basis

TTM ended 2026-09-30 · Balance sheet at 2026-09-30 · Annual history · FY 2025

Latest source filing: 2026-11-12

Score computed: 2026-11-14

Annual history · FY 2025

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · TTM ended 2026-09-30

Latest source filing: 2026-11-12

Score computed: 2026-11-14

Annual history · FY 2025

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · TTM ended 2026-09-30 · Balance sheet at 2026-09-30 · Market data at 2026-11-01

Latest source filing: 2026-11-12

Score computed: 2026-11-14

Qualitative assessment · Annual history · FY 2025

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Qualitative assessment · Annual history · FY 2025

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · Qualitative assessment

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · Qualitative assessment

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · TTM ended 2026-09-30 · Market data at 2026-11-01

Latest source filing: 2026-11-12

Score computed: 2026-11-14

Annual history · FY 2025 · Price history 2025-01-01–2026-11-01

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · Qualitative assessment

Latest source filing: 2026-03-26

Score computed: 2026-11-14

TTM ended 2026-09-30 · Balance sheet at 2026-09-30 · Price history 2025-01-01–2026-11-01 · Annual history · FY 2025

Latest source filing: 2026-11-12

Score computed: 2026-11-14

Annual history · FY 2025

Latest source filing: 2026-03-26

Score computed: 2026-11-14

Annual history · FY 2025 · Balance sheet at 2026-09-30

Latest source filing: 2026-11-12

Score computed: 2026-11-14

TTM ended 2026-09-30 · Annual history · FY 2025 · Price history 2025-01-01–2026-11-01

Latest source filing: 2026-11-12

Score computed: 2026-11-14

Where It Passes

  • Valuation models100% pass✓ 2▾

    SPRO undervalued: all 2 models price fair value above $1.00 (median $2.08)

    Graham fair value$1.88
    ✓Graham+46.8% margin vs $1.00
    Pabrai fair value$2.29
    ✓Pabrai+56.3% margin vs $1.00

Where It Falls Short

  • Growth0% pass✓ 3✗ 10▾

    No clean pass — all 8 investors flag at least one growth criterion

    EPS Growth (3-yr avg, 10-yr window)
    ✗Graham>= 33% growth
    Basic earnings-growth PEG (dividends excluded)P/E 6.7x (growth N/A)
    ✗Lynch< 1.0 (ideally < 0.5)
    3-5 Year EPS CAGR
    ✗Lynch15-30% (Fast Grower); > 0% to pass
    Inventory Growth vs Revenue GrowthN/A (no inventory)
    ✓LynchInventory growth < Revenue growth
    EPS Growth Direction
    ✗DremanPositive over recent years
    EPS CAGR
    ✗Dreman> 5% annualized
    Positive Net Income Frequency2/11 years positive
    ✗MarksPositive net income in >= 7 of last 10 years
    3yr Median Revenue Growth39.2%
    ✓Ackman>= 5%
    Positive EPS Growth Frequency
    ✗AckmanPositive EPS growth in >= 3 of last 5 years
    5-Year EPS CAGR
    ✗Templeton> 0% (5-year EPS CAGR)
    Revenue growth vs. gross and operating margin trendrevenue flat/down, operating margin 20.7% -> 9.5%
    ✗SleepRevenue rising; gross margin flat or falling; operating margin holding
    5-year Revenue CAGR48.2%
    ✓SleepCAGR > 7%
    3-5 Year Diluted EPS CAGR
    ✗Neff7%-20% annualized
  • Profitability6% pass✓ 6✗ 29▾

    15 of 16 flag SPRO's profitability — Graham, Buffett, Lynch +12 more

    Positive EPS (10 years)2/12 years positive
    ✗GrahamPositive EPS every year for 10 years
    EPS Growth (3-yr avg, 10-yr window)
    ✗Graham>= 33% growth
    Net Income Positive (10+ years)2/12 years positive
    ✗BuffettPositive every year for 10+ years
    ROE (up to 5-year arithmetic mean)-55.1%
    ✗Buffett> 15% arithmetic mean (app rule)
    Operating Margin (10-yr trend)9.5% (latest)
    ✓BuffettStable or rising over 10 years
    Free Cash Flow Proxy$-77.7M
    ✗BuffettPositive and growing
    Earnings Variance (10-yr CoV)
    ✗BuffettCoV < 0.3
    Retained Earnings Effectiveness
    ✗Buffett$1 retained -> > $1 market value created
    Basic earnings-growth PEG (dividends excluded)P/E 6.7x (growth N/A)
    ✗Lynch< 1.0 (ideally < 0.5)
    3-5 Year EPS CAGR
    ✗Lynch15-30% (Fast Grower); > 0% to pass
    ROE-3778.9%
    ✗Lynch> 15%
    EBIT / Enterprise Value35.1%
    ✓Greenblatt> 10%
    Earnings Yield + ROC AssessmentEY=35.1%, ROC=None
    ✗GreenblattBoth EY > 10% and ROC > 25%
    Net Income / Total Assets12.44%
    ✓PiotroskiROA > 0
    ROA Change YoY-62.03% -> 12.44% (delta: +74.46%)
    ✓PiotroskiCurrent ROA > Prior ROA
    (CFO / Total Assets) vs ROACFO/Assets=-18.32%, ROA=12.44%
    ✗PiotroskiCFO/Assets > ROA
    Gross Margin Change YoY
    ✗PiotroskiImproved YoY
    Pre-Tax Income / Revenue13.2%
    ✓Dreman>= 8%
    Net Income / Shareholders' Equity-3778.9%
    ✗Dreman> 12%
    Margin of SafetyP/E=6.7x, P/B=1.0x
    ✓PabraiP/B < 1.5 or P/E < 15
    Return on Equity-37.6% (3-yr avg)
    ✗AkreROE > 20% (3-year avg)
    Discount to Intrinsic ValueN/A (negative normalized EPS)
    ✗Marks>= 20% below intrinsic value
    Positive Net Income Frequency2/11 years positive
    ✗MarksPositive net income in >= 7 of last 10 years
    Operating Income / Revenue-67.3%
    ✗Ackman>= 15%
    Net Income / Shareholders Equity-3778.9%
    ✗Ackman>= 15%
    5-Year EPS CAGR
    ✗Templeton> 0% (5-year EPS CAGR)
    Operating Margin Trend20.7% (2023) -> 9.5% (2025)
    ✗TempletonNon-negative operating-margin trend over 3 years
    Revenue growth vs. gross and operating margin trendrevenue flat/down, operating margin 20.7% -> 9.5%
    ✗SleepRevenue rising; gross margin flat or falling; operating margin holding
    Net income / market capitalization-50.66%; #5060/6340 (top 79.8%)
    ✗AsnessTop 30% of eligible cross-section✗OshaughnessyTop 10% of eligible cross-section
    Gross profit / total assets
    ✗AsnessTop 30% of eligible cross-section
    Net income / positive book equity-3778.87%; #5202/5226 (top 99.5%)
    ✗AsnessTop 30% of eligible cross-section
    Negative 5-year standard deviation of ROA-0.3188; #4640/5884 (top 78.9%)
    ✗AsnessTop 30% of eligible cross-section
    3-5 Year Diluted EPS CAGR
    ✗Neff7%-20% annualized
    Positive Diluted-EPS Years2/10 years positive
    ✗Schloss>= 70% positive over 5-10 observed years (app rule)
  • Debt & Leverage8% pass✓ 3✗ 12▾

    11 of 12 flag SPRO's debt & leverage — Graham, Buffett, Lynch +8 more

    LT Debt vs Net Current Assets
    ✗GrahamLT Debt <= Net Current Assets
    Debt/Equity & Interest Coverage
    ✗BuffettD/E < 0.5 AND Interest Coverage > 5x
    Total Debt / Equity
    ✗Lynch< 0.33
    Cash - Long-term Debt
    ✗LynchPositive preferred
    LT Debt / Total Assets Change0.00% -> 0.00%
    ✓PiotroskiDecreased YoY
    Current Assets / Current Liabilities1.92
    ✓Dreman> 1.5✓SchlossCurrent ratio >= 1.50x (app cutoff)
    Total Debt / Shareholders' Equity
    ✗Dreman< 0.8✗Templeton< 1.0 (fixed cap; proxy for below-sector-median leverage)✗SchlossD/E < 1.00x
    Debt Levels
    ✗MungerDebt/Equity < 0.5✗AkreDebt/Equity < 0.3
    Interest Coverage & Debt/EBITDA
    ✗MarksInterest Coverage > 3x; Debt/EBITDA < 4x
    Total Debt / Shareholders Equity
    ✗Ackman<= 1.0
    Negative debt-to-equity (higher means less debt)
    ✗AsnessTop 30% of eligible cross-section
  • Verdicts8% pass✓ 1✗ 12▾

    Split decision: 12 FAIL · 3 NEUTRAL · 1 PASS

    Overall verdict
    ✗GrahamFAIL (1/9)✗BuffettFAIL (1/9)✗LynchFAIL (1/7)•GreenblattNot ranked✓PiotroskiPASS (F-Score 5)✗DremanFAIL (4/11)✗MungerFAIL (1/4)•PabraiNEUTRAL (2/3)✗AkreFAIL (0/6)✗MarksFAIL (1/5)✗AckmanFAIL (2/9)✗TempletonFAIL (3/8)✗SleepFAIL (1/6)•AsnessNEUTRAL (Not ranked)✗NeffFAIL (2/6)✗SchlossFAIL (2/7)•OshaughnessyNEUTRAL (Not ranked)
  • Cash Flow10% pass✓ 1✗ 11▾

    9 of 10 flag SPRO's cash flow — Buffett, Lynch, Piotroski +6 more

    Free Cash Flow Proxy$-77.7M
    ✗BuffettPositive and growing
    FCF Positive and Growing$-86.0M
    ✗LynchPositive and growing
    Operating Cash Flow$-12.6M
    ✗PiotroskiCFO > 0
    (CFO / Total Assets) vs ROACFO/Assets=-18.32%, ROA=12.44%
    ✗PiotroskiCFO/Assets > ROA
    Price / (CFO / Shares)N/A (negative CFPS)
    ✗Dreman< 8x
    P/E or FCF YieldP/E=6.7x
    ✓PabraiP/E < 15 or FCF Yield > 10%
    FCF Positive0/6 years FCF positive
    ✗MarksPositive FCF in majority of recent years
    (OCF - CapEx) / Market Cap
    ✗Ackman>= 4%
    Price / FCF per Share
    ✗Ackman<= 25
    Positive Operating Cash Flow frequency0/11 years positive
    ✗SleepPositive OCF in >= 70% of available years
    Operating Cash Flow - Capital Expenditures
    ✗Neff> $0 (app proxy for a strong fundamental case)
    (Operating cash flow - capex) / market capitalization
    ✗OshaughnessyTop 10% of eligible cross-section
  • Valuation15% pass✓ 11✗ 17▾

    11 of 13 flag SPRO's valuation — Graham, Lynch, Greenblatt +8 more

    Price / Book Value per Share1.0x
    ✓Dreman< 1.2x✓Templeton< 1.5x✗SchlossP/B <= 0.80x (app cutoff)
    Price / 3-yr avg EPS
    ✗Graham<= 15x
    Price-to-Book Ratio1.0x
    ✓Graham<= 1.5x
    P/E x P/B
    ✗Graham<= 22.5
    Basic earnings-growth PEG (dividends excluded)P/E 6.7x (growth N/A)
    ✗Lynch< 1.0 (ideally < 0.5)
    EBIT / Enterprise Value35.1%
    ✓Greenblatt> 10%
    Earnings Yield + ROC AssessmentEY=35.1%, ROC=None
    ✗GreenblattBoth EY > 10% and ROC > 25%
    Price / EPS6.7x
    ✓Dreman< 12x✓Templeton< 12x (fixed ceiling; proxy for the market's cheapest 40%)
    Price / (CFO / Shares)N/A (negative CFPS)
    ✗Dreman< 8x
    Valuation ReasonablenessP/E=6.7x, OE Yield=15.2%
    ✓MungerP/E < 25 or Owner Earnings Yield > 5%
    P/E or FCF YieldP/E=6.7x
    ✓PabraiP/E < 15 or FCF Yield > 10%
    P/B or P/E vs. Historical AverageP/E=6.7x, P/B=1.0x
    ✓MarksP/E < 15 or P/B < 2.0
    Discount to Intrinsic ValueN/A (negative normalized EPS)
    ✗Marks>= 20% below intrinsic value
    Price / FCF per Share
    ✗Ackman<= 25
    Price vs. Trailing Low152% of trailing low ($0.66)
    ✗Templeton<= 120% of trailing low (certified split-adjusted live window)
    Net income / market capitalization-50.66%; #5060/6340 (top 79.8%)
    ✗AsnessTop 30% of eligible cross-section✗OshaughnessyTop 10% of eligible cross-section
    Positive book equity / market capitalization+0.0134; #5168/6449 (top 80.1%)
    ✗AsnessTop 30% of eligible cross-section
    Price / Diluted EPS6.7x
    ✓NeffP/E <= 15x (app proxy for a P/E 40%-60% below the market)
    (EPS CAGR % + Dividend Yield %) / P/E
    ✗Neff> 0.7 (Neff's published traditional edge)
    Price / Tangible Book Value per Share0.96x
    ✓SchlossP/TBV <= 1.00x (app cutoff)
    Book Value per Share Change
    ✗SchlossLatest BVPS >= earliest BVPS over >= 3 years (app rule)
    Revenue / market capitalization+0.7133; #2178/5247 (top 41.5%)
    ✗OshaughnessyTop 10% of eligible cross-section
    (Operating cash flow - capex) / market capitalization
    ✗OshaughnessyTop 10% of eligible cross-section
    Trailing six-month price return through the evaluation date-62.55%; #5463/6202 (top 88.1%)
    ✗OshaughnessyTop 10% of eligible cross-section
  • Efficiency25% pass✓ 3✗ 8▾

    6 of 8 flag SPRO's efficiency — Graham, Buffett, Greenblatt +3 more

    Current Ratio1.92
    ✗Graham>= 2.0
    ROIC (3-5 yr avg)
    ✗Buffett> 10%
    ROIC - WACC
    ✗BuffettPositive (WACC = 10%)
    EBIT / (NWC + Net Fixed Assets)
    ✗Greenblatt> 25%
    Current Ratio Change YoY2.19 -> 7.59
    ✓PiotroskiIncreased YoY
    Revenue / Total Assets Change YoY0.43x -> 0.97x
    ✓PiotroskiImproved YoY
    Current Assets / Current Liabilities1.92
    ✓Dreman> 1.5
    Return on Invested Capital
    ✗Munger> 15%
    ROIC (high and growing)FY2023: ROIC=unavailable; FY2024: ROIC=unavailable; FY2025: ROIC=unavailable
    ✗AkreLatest 3 consecutive FYs: ROIC > 15% in each
    Reinvestment Rate x ROIC
    ✗AkreReinvestment Rate * ROIC > 10%
    ROIC (5-year)
    ✗SleepROIC > 12% in a majority of years

Business & financials

Financial snapshot: annual FY 2025. Current investor scores may use newer quarterly data.

Company Profile

Industry: Pharmaceutical Products
SIC Sector: Chemicals & Pharmaceuticals
Size: Micro Cap($58.3M)
Revenue: $66.8M+39.2% YoY
Net Income: $8.6M+112.5% YoY

Financial Snapshot

Operating Margin9.5%
Return on Equity14.5%
Debt / Equity--
Current Ratio7.59
EPS (Diluted)$0.15
Shares Retired−3.3% / −4.7% 2y

Similar Companies

MRKMerck & Co., Inc.
$364.3B
ABTABBOTT LABORATORIES
$188.0B
BMYBRISTOL MYERS SQUIBB CO
$129.7B
TECHBIO-TECHNE Corp
$11.4B

Shareholder Return

Fiscal 2025

Issued 3.3% of shares last year, 4.7% issued over two.

Buybacks
—
Dividends
—

Company Financials

Latest TTM and quarters alongside annual years

TTM sums four consecutive quarters and uses the latest quarter-end balances. Quarter columns show three-month results; annual columns show full-year totals. Growth compares the same period a year earlier. EPS is not added for TTM; full-year ratios are blank for quarters.

The latest annual period end is unavailable. Showing the latest fiscal cycle’s quarters; quarter and annual columns may overlap. Quarterly shows the full quarter history.

MetricTTM · 2026-09-30

2025-10-01 – 2026-09-30

Sources · derived quarter values

Derived from cumulative filings: revenue, net income, operating income, ebit, operating cash flow, depreciation amortization.

Q3 FY 2026

2026-07-01 – 2026-09-30

Sources · derived quarter values

Derived from cumulative filings: operating cash flow.

Q2 FY 2026

2026-04-01 – 2026-06-30

Sources · derived quarter values

Derived from cumulative filings: operating cash flow.

Q1 FY 2026

2026-01-01 – 2026-03-31

Sources
FY 2025
Sources
  • 10-K · 2026-03-26
FY 2024
Sources
  • 10-K · 2025-03-27
FY 2023
Sources
  • 10-K · 2024-03-13
FY 2022
Sources
  • 10-K · 2023-03-30
FY 2021
Sources
  • 10-K · 2022-03-31
Market Cap$58.3Mcurrent------$123.5Mest.$46.8Mest.$81.9Mest.$97.3Mest.$388.8Mest.
Revenue$41.6M↑2%$0↓100%$0↓100%$258.0K↓96%$66.8M↑39%$48.0M↓54%$103.8M↑94%$53.5M↑193%$18.3M
Operating Income-$28.0M↑40%-$41.9M↓429%-$9.9M↓306%-$7.5M↑49%$6.3M↑109%-$73.4M↓442%$21.5M↑151%-$42.2M↑52%-$88.0M
Net Income-$29.5M↑33%-$44.3M↓500%-$9.6M↓462%-$7.2M↑48%$8.6M↑113%-$68.6M↓401%$22.8M↑149%-$46.4M↑48%-$89.8M
EPS (Diluted)--$-0.76↓485%$-0.16↓433%$-0.13↑48%$0.15↑112%$-1.27↓395%$0.43↑135%$-1.23↑58%$-2.91
Gross Margin—————————
Operating Margin-67.3%↑42%——-2921.7%↓1065%9.5%↑106%-152.9%↓839%20.7%↑126%-78.9%↑84%-481.9%
ROE-3778.9%↓2184%———14.5%↑110%-148.7%↓797%21.3%↑135%-61.1%↑40%-101.7%
Total Debt------------------
Shareholders' Equity$781.0K↓97%$781.0K↓97%$44.2M↑35%$52.9M↑57%$59.0M↑28%$46.1M↓57%$106.9M↑41%$75.9M↓14%$88.3M
Current Ratio1.92↓50%1.92↓50%6.12↑54%10.50↑310%7.59↑247%2.19↓38%3.53↓33%5.25↓38%8.46
Debt / Equity—————————
Operating Cash Flow-$40.4M↓46%-$42.6M↓345%-$5.4M↑70%$15.9M↑496%-$12.6M↑46%-$23.4M↑29%-$33.0M↓327%-$7.7M↑88%-$64.3M
Free Cash Flow------------------

Score history

Historical Score Timeline

Industry peers

Industry Peers

Similar companies in Pharmaceutical Products

SPRO vs Peers — Financial Grading

Revenue$66.8MBottom 25%
Net Income$8.6MMedian
ROE14.5%Top 25%
D/E—
Op. Margin9.5%Median
Curr. Ratio7.59Top 25%
CompanyMarket CapPriceRevenueNet IncomeROED/EOp. MarginCurr. RatioGrahamBuffettLynchGreenblattPiotroskiDreman
Merck & Co., Inc.MRK$364.3B$147.76$65.0B$18.3B34.7%0.94—1.542/95/94/70/3F-Score 41/11
ABBOTT LABORATORIESABT$188.0B$108.52$44.3B$6.5B12.5%0.2518.2%1.583/94/92/71/3F-Score 53/11
BRISTOL MYERS SQUIBB COBMY$129.7B$63.43$48.2B$7.1B38.2%2.4419.4%1.262/91/93/71/3F-Score 85/11
BIO-TECHNE CorpTECH$11.4B$72.80$1.2B$73.4M3.8%—8.4%3.464/93/93/70/3F-Score 54/11
REPLIGEN CORPRGEN$10.7B$167.79$738.3M$48.9M2.3%0.267.5%8.373/92/93/70/3F-Score 75/11
IONIS PHARMACEUTICALS INCIONS$4.8B$29.06$943.7M$381.4M-78.0%3.60-40.4%3.833/91/91/70/3F-Score 43/11
NEOGEN CORPNEOG$2.5B$11.23$870.4M$7.9M-0.4%0.76-2.5%3.823/91/92/70/3F-Score 64/11
Pharvaris N.V.PHVS$2.4B$33.36—$206.4M-64.8%0.00——0/90/92/70/3F-Score 22/11