Is SPRO diluting shareholders?

Read three numbers together: shares outstanding over time (58.2M as of 2026-08-07), warrants that can convert into new shares, and how much cash runway remains (~48.26425855513308 months). A company short on cash with live registrations is structurally likely to issue shares.

Where do these numbers come from?

SEC EDGAR only: the XBRL company-facts API for shares, warrants and cash, and filing metadata for registrations and pricings. Every figure shows its source form, and nothing here is estimated by us beyond the arithmetic stated next to it.

Why might a warrant tranche be missing from the table?

The tranche table is built from the dimensions the company tagged in its own 10-Q or 10-K XBRL. A tranche the filer chose not to dimension does not appear, and its absence proves nothing: the exhibits remain the ground truth. Everything shown carries the filing it came from.

Dilution profile // every instrument, one screen, from SEC filings

Spero Therapeutics, Inc. (SPRO)

CIK 1701108 · all EDGAR filings →

Overall dilution risk

HIGHworst of 3 computed sub-ratings (offering ability)

= the worst band among the computed sub-ratings, no hidden weighting

not every sub-rating was computable; treat as a floor

Offering ability

HIGH$300M registered

= total registered offering amount from the fee exhibits of live registrations (bands: $1M / $20M)

one or more live registrations had no structured fee data, so the true total is AT LEAST this

Overhead supply

NOT COMPUTEDno warrant count tagged in XBRL

= warrant shares outstanding divided by current shares outstanding

absence of a tag is not proof of absence of warrants

Historical dilution

LOW+10% O/S in 3y

= share count now vs 3 years ago (bands: 30% / 100%); a reverse split pushes this negative

Cash need

LOW~48.3 months of runway

= cash vs trailing operating burn (bands: 6mo / 24mo; positive operating CF = low)

the company itself flagged going-concern doubt

Same rating bands the category standard uses, but free, with the formula on the chip and the gaps in the data said out loud.

Shares outstanding over time

Latest: 58.2M shares as of Aug 7, 2026 (10-Q).

⊙

EVIDENCE — filed/published fact

SourceSEC XBRL, cover-page share count

Fielddei:EntityCommonStockSharesOutstanding

As of2026-08-07

HowThe newest cover-page count as filed, whatever its age. The float checker applies a 200-day freshness rule and sets this beside the balance-sheet count.

Open the source document →

Cash runway

Going-concern warning

auditor flagged substantial doubt

The company itself flagged going-concern doubt in a filing.

Full breakdown: cash runway tool · source filing →

Warrants

No warrant figures tagged in this filer’s XBRL facts. That means the company has not reported them in structured form; it does not prove no warrants exist. The exhibits are the ground truth.

Convertible notes

No convertible-note facts tagged in the 10-Q filed Aug 12, 2026. If convertible notes exist, their terms live in exhibit prose for this filer and are not parsed; absence of a tag is not proof of absence. The exhibits are the ground truth.

Registrations and offerings

Registered offering capacity on live registrations: $300.0Mfrom the structured fee exhibits; registered is not remaining, takedowns are not subtracted

S-3Aug 28, 2026$300.0M registeredfiling →

S-3Mar 15, 2024no structured fee exhibit in this filing (predates fee-data XBRL or fee deferred)filing →

Last 12 months: 0 executed · 1 registered.

EFFECTIVESep 10, 2026SEC declared a registration effective — selling can beginEFFECT →

REGISTEREDAug 28, 2026S-3 registration — capacity to sell shares, not a sale yetS-3 →

EFFECTIVEMar 22, 2024SEC declared a registration effective — selling can beginEFFECT →

REGISTEREDMar 15, 2024S-3 registration — capacity to sell shares, not a sale yetS-3 →

EXECUTEDSep 22, 2022Unregistered share sale disclosed (8-K item 3.02)8-K →

EXECUTEDJul 1, 2021Unregistered share sale disclosed (8-K item 3.02)8-K →

EFFECTIVEMar 29, 2021SEC declared a registration effective — selling can beginEFFECT →

REGISTEREDMar 11, 2021S-3 registration — capacity to sell shares, not a sale yetS-3 →

EXECUTEDNov 13, 2020Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)424B5 →

EXECUTEDSep 14, 2020Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)424B5 →

EXECUTEDSep 9, 2020Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)424B5 →

EXECUTEDFeb 11, 2020Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)424B5 →

Full history and shelf status: offering checker · S-3 shelf checker

Source: SEC EDGAR XBRL company facts and filing metadata, fetched live and cached briefly. Share counts are cover-page figures with their form named. Warrant tranches and convertible notes come from the dimensioned facts in the latest 10-Q/10-K instance document, exactly as the company tagged them; untagged tranches and notes are absent, not disproven. Nothing on this page is manually verified and nothing is behind a login: what free data supports is shown, what it cannot support is stated. Not investment advice.

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