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Spero Therapeutics, Inc.

SPRO · Healthcare · $68.3M mkt cap · FY2025 filings · · Shallow moat ·

Doesn't clear the bar

Shallow moat
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The five investor questions

65

2021–2025 (latest 5 aligned FYs; v3 window cap 5): revenue $3.1M to $12.6M, increasing; diluted EPS -2.91 to 0.15, increasing.

—

Not enough years of gross-margin data to score pricing power.

14

Median ROIC -41.5%, above the 12% hurdle in 40% of years.

100

Net cash position — no leverage risk.

44

Owner earnings changed trend unclear over up to the ten most recent annual observations, share count n/a.

The pricingPower component abstained: Not enough years of gross-margin data to score pricing power. The other four 20% weights were renormalized over the scored 80%.

Price vs. value if growth stopped today

A cautious baseline, not a price target: what the shares may support if normalized owner earnings simply hold steady.

Above value if growth stopped todayBelow value if growth stopped today
No price data
Not reported
Unavailable — insufficient owner-earnings data
Unavailable — insufficient growth-model data
$1.21
No price data

This zero-growth estimate assumes trailing owner earnings persist — unreliable for declining businesses. The recent FY revenue series does not trigger the three-consecutive-declines flag.

Among the current top-score group, the median current price is 238% above the zero-growth estimate across 49 of the current top 50 companies by Moat Score with both values.

Score records captured Sep 4, 2026.

Exactly which 50 companies?

FTNT, META, MEDP, IBEX, MSFT, GOOG, LULU, ANF, IDXX, TXRH, FHI, QLYS, FFIV, ADBE, LLY, MANH, VEEV, RMD, GRMN, PCTY, EAT, UI, SSD, MNST, DOCS, LRCX, MCO, CPRT, NTAP, NVDA, CORT, SFM, MPTI, ULTA, SN, ROL, CTAS, PAYC, IRMD, INTU, DECK, MORN, JKHY, TPR, LGCY, DAL, GWW, ISRG, MPWR, LOPE

Missing a usable price or zero-growth estimate: ANF.

Model details under moat-index@3.0.0: zero-growth multiple 11.1×, capped-growth comparison at no more than 18×; 9% discount rate; high-end growth 0% (capped at 4%) using min(5y revenue CAGR, 5y diluted-EPS CAGR), clamped to 0%–4%; maintenance capex uses min(capex, D&A); abstain when D&A is unavailable. This is a disclosed model range, not intrinsic value as fact.

12 years of fundamentals

The business, in plain English

Across the filed record, revenue grew from $335000 (FY2016) to $12.6M (FY2025) — about 49.6% a year compounded over 9 years.

It earned 32.7% on invested capital in the latest filed year, FY2025. Across the full 5-year measurable filed record, median ROIC was −41.5%. Over the v3 recent window (5 measurable filed years), median ROIC was −41.5%. The Returns on Capital filter above scores it 14/100.

SPRO's latest filed year, FY2025, doesn't disclose total debt in a form the methodology can use, so current leverage is treated as unmeasured — never assumed to be zero.

This breakdown is generated from the filed numbers and sub-scores above — no outside narrative, no estimates. Where a filing doesn’t disclose an input, the sentence that would need it is omitted instead of guessed.

FY2014–FY2025 · 12 fiscal years, normalized from SPRO’s SEC filings

Sales, as filed$12.6M FY2025
$0$5M$10M2014201820222025
Revenue kept after cost of goods

Not disclosed in SPRO’s filings for these years — we don’t estimate it.

Standard ROIC or separately labeled Operating ROIC

Exact FY and FY-1 financing invested-capital inputs are required.

Exact FY and FY-1 financing invested-capital inputs are required.

Cash an owner could take out$8.6M FY2025
−$50M$02014201820222025

The explained ROIC gaps have filed inputs but no meaningful positive invested-capital denominator. Other gaps mean the item is not in the filings for that year. The series is never interpolated or estimated. The Table view lists every filed value, including operating and net margins, total debt, and share count.

Flagship explainer

How Spero Therapeutics, Inc. makes its money

Spero Therapeutics, Inc.'s filing does not supply enough comparable lines for a truthful flow chart — here's what is filed:

Table alternative
Filed lineValue% of revenueSource
$12.6M100%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
$6.3M50%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Income before tax$8.8M70%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Income tax$2610002%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
$8.6M68%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Source:
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
· event Dec 31, 2025 · retrieved Sep 4, 2026 · annual-row source set

Flagship explainer

What Spero Therapeutics, Inc. owns — and owes

Spero Therapeutics, Inc.'s filing tags don't support a full breakdown — here's what is filed:

Table alternative
Filed lineValue% of assetsSource
Total assets$68.9M100%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Cash and equivalents$40.3M58%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Stockholders’ equity$59M86%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Source:
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
· event Dec 31, 2025 · retrieved Sep 4, 2026 · annual-row source set

Flagship explainer

What drives Spero Therapeutics, Inc.’s return on equity?

ROE is five filed business factors multiplied together.

DuPont return on equity factor treeReturn on equity branches into tax burden, interest burden, operating margin, asset turnover, and the equity multiplier.Return on equity16%Tax burden97%net income ÷ pretax incomeInterest burden140%pretax ÷ operating incomeOperating margin50%operating income ÷ revenueAsset turnover0.14×revenue ÷ average assetsEquity multiplier1.71×average assets ÷ average equityAs of 2025-12-31 · 1 SEC filing sourceBuy Like Buffett · buylikebuffett.com
DuPont source inputs
InputValueFiscal yearSource
$8.6MFY2025
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Income before tax$8.8MFY2025
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Operating income$6.3MFY2025
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
$12.6MFY2025
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Ending assets$68.9MFY2025
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Beginning assets$111MFY2024
  • 10-K · FY 2024Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
$59MFY2025
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
$46.1MFY2024
  • 10-K · FY 2024Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Source: · event Dec 31, 2025 · retrieved Sep 4, 2026 · annual-row source set
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Flagship explainer

Where Spero Therapeutics, Inc.'s cash went

Spero Therapeutics, Inc.’s filing does not supply enough provenance-matched cash-flow lines for a truthful flow chart — here’s what is filed:

Table alternative
Filed lineValue% of cash from operationsSource
Cash from operations−$12.6M−100%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Depreciation and amortization$00%
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
Source:
  • 10-K · FY 2025Filing detailsAccession 0001193125-26-126192 · filed Mar 26, 2026
· event Dec 31, 2025 · retrieved Sep 4, 2026 · annual-row source set

Curated 19-manager tier

Who reported holding Spero Therapeutics, Inc.

Delayed public 13F reports for 2026-Q2—not live positions, trades, or recommendations.

0 holding0 exited0 not holding0/19 resolved19 not retrieved

Named manager positions and quarter-over-quarter changes
ManagerReported positionQuarter-over-quarterFiling accession
Abrams CapitalNot retrievedComparison not retrievedFiling not retrieved
Akre CapitalNot retrievedComparison not retrievedFiling not retrieved
Baupost GroupNot retrievedComparison not retrievedFiling not retrieved
Berkshire HathawayNot retrievedComparison not retrievedFiling not retrieved
Brave Warrior AdvisorsNot retrievedComparison not retrievedFiling not retrieved
Dodge & CoxNot retrievedComparison not retrievedFiling not retrieved
First EagleNot retrievedComparison not retrievedFiling not retrieved
FundsmithNot retrievedComparison not retrievedFiling not retrieved
Gardner Russo & QuinnNot retrievedComparison not retrievedFiling not retrieved
Gates Foundation TrustNot retrievedComparison not retrievedFiling not retrieved
Mairs & PowerNot retrievedComparison not retrievedFiling not retrieved
Markel / Markel-GaynerNot retrievedComparison not retrievedFiling not retrieved
Oakmark / Harris AssociatesNot retrievedComparison not retrievedFiling not retrieved
Pershing SquareNot retrievedComparison not retrievedFiling not retrieved
Polen CapitalNot retrievedComparison not retrievedFiling not retrieved
Sequoia / Ruane CunniffNot retrievedComparison not retrievedFiling not retrieved
Southeastern Asset ManagementNot retrievedComparison not retrievedFiling not retrieved
Tweedy, BrowneNot retrievedComparison not retrievedFiling not retrieved
Yacktman Asset ManagementNot retrievedComparison not retrievedFiling not retrieved

Position size uses shares and filed value from each manager’s 13F. Portfolio weight uses the eligible long-share filing denominator. Changes compare only with the immediately preceding calendar quarter.

Source: Filing source not retrieved · event Jun 30, 2026 · retrieved Sep 4, 2026

Flagship explainer

What Spero Therapeutics, Inc. insiders reported

We could not retrieve insider activity for this rendering; no zero-activity claim is shown.

Unavailable: Form 4 activity could not be retrieved for this rendering.

Moat Score history

16 logged readings since Jul 17, 2026 · append-only, never rewritten

Moat Score over timeLast scored reading of each day, on the 0–100 scale55.7 / 100
0406080100WideNarrowShallowNo moatJul 20, 2026Sep 4, 2026

Breaks in the line mark methodology or normalizer upgrades — readings across versions aren’t compared, so a level shift there isn’t a change in the business.

Tier changesSame-methodology and same-normalizer crossings of the Wide / Narrow / Shallow bars

  1. Normalizer upgraded unstamped (version unknown)moat-xbrl-normalizer@1.1.0 — readings across versions aren’t comparedJul 26, 2026
  2. Methodology upgraded moat-index@2.0.0moat-index@3.0.0 — readings across versions aren’t comparedJul 23, 2026
  3. Methodology upgraded moat-index@1.2.0moat-index@2.0.0 — readings across versions aren’t comparedJul 20, 2026

Scores are logged append-only and never overwritten — this record cannot be reconstructed retroactively, which is exactly why it’s worth keeping.

Insider activity

Form 4 reports mix P/S market or private transactions with compensation-plan mechanics. Activity casually described as “insider selling” can include compensation mechanics; awards, tax withholding, and option exercises are shown by their exact filed class here, never collapsed into “Bought” or “Sold.”

These are disclosed filing facts and arithmetic aggregates, not a signal or verdict.

The insider-filing service is temporarily unavailable, so no partial or guessed answer is shown for SPRO.

Track record

How Spero Therapeutics, Inc.’s moat rated in each of the years we can reconstruct from its filings — scored only on what was knowable at the time — and what its price and returns did afterward. The score never saw a price; the two are joined only in hindsight, for education, not as a signal.

Point-in-time scores 2017–2025, one methodology version · reconstructed from filings on file each Dec 31 — never with hindsight

Point-in-time Moat Score (dot colored by tier)Indexed price (total-return (dividends reinvested))Rated Wide-moat that year

How to read this: each dot is what the engine would have scored SPRO on that December 31; the line below is its total-return price path (dividends reinvested) in the years since.

0406080100WideNarrowShallowNo moatPoint-in-time Moat Score102050100Indexed price · log scale (2018 = 100)201720192021202320252026

Two tracks, one timeline: the score has its own 0–100 scale (top), the price its own 100-based scale (bottom) — never a shared axis. The price path is a total-return (dividends reinvested) index built from the same data the forward returns use; gaps in the score line are years with no reconstructed rating (see the table for why). The Table view carries every value.

What followed, in the years it rated Wide

In the reconstructed history shown, SPRO did not rate Wide-moat in any year, so there is no wide-moat track record to report. That absence is itself the honest answer — we don’t manufacture a comparison where the rating never earned one.

Healthcare context

#134 of 708 scored Healthcare companies, ranked by Moat Score.

Nearest peers by Moat Score

  1. #132KROS KEROS THERAPEUTICS, INC.56.1Shallow moat
  2. #133COHR COHERENT CORP.55.9Shallow moat
  3. #135PNTG THE PENNANT GROUP, INC.55.7Shallow moat
  4. #136MMM 3M COMPANY55.6Shallow moat

Compare SPRO with its nearest peers →All Healthcare companies on the Index →

Common questions about SPRO

Does Spero Therapeutics, Inc. have an economic moat?
Based on its FY2025 SEC filings, the Moat Index scores Spero Therapeutics, Inc. (SPRO) 55.7 out of 100 — a Shallow moat. The five questions behind that score begin at 20% each; if exactly one genuinely lacks data, the other four weights are renormalized and disclosed. revenue and EPS trend 65, pricing power not measurable from the filings, returns on capital 14, balance-sheet safety 100, capital allocation 44.
How has SPRO's Moat Score changed over time?
The record logs 16 readings since Jul 17, 2026; the latest reads 55.7 out of 100 (shallow moat). No tier changes on record yet. (Methodology or normalizer upgrades on Jul 20, 2026, Jul 23, 2026, Jul 26, 2026 re-based the score; readings across versions aren't compared.) The history is append-only — readings are only ever added, never rewritten.

Scored from primary SEC filings via the public methodology. Educational only — not a recommendation to buy or sell SPRO. See the disclaimer.