What Is Float in Stocks: Definition, Calculation, and Why Two Sources Disagree

Direct answer: The float of a stock is the number of shares actually available for trading by the general public. You calculate it by subtracting the restricted shares — those held by executives, affiliates, and shares under lock-up — from the shares outstanding. This number is read in SEC filings (10-Q, 10-K, 424B prospectus) and changes with every dilution event.

What is the float of a stock?

The float (or free float, or public float) is the number of a company's shares that are actually available to be bought and sold by public investors. It's a subset of the shares outstanding: you remove the shares held by insiders (executives, founders), by affiliates, and the shares temporarily locked up by a lock-up agreement.

On a small-cap that gaps, the float is often the most-watched number: it determines how many shares really "move" for a given volume. A small float means that the same volume represents a larger share of the tradable shares.

Float vs shares outstanding: the distinction that matters

These are two different numbers, and confusing them is one of the leading causes of float error.

Term	Definition	Where to read it
Shares outstanding	All shares issued and held by everyone, insiders included.	Cover page of the 10-Q / 10-K, SEC EDGAR filings
Float / free float	Shares outstanding minus the restricted shares (insiders, affiliates, lock-up).	Calculated from the 10-Q/10-K + Form 4 / beneficial ownership tables
Public float (SEC sense)	Market value of shares held by non-affiliates, used to classify the issuer.	Cover page of annual 10-K reports

Simple rule: float ≤ shares outstanding, always. If a source gives you a float higher than the shares outstanding, there's an error.

How to calculate the float

The basic formula:

Float = Shares outstanding − Shares held by insiders/affiliates − Shares under lock-up

Steps to rebuild it from primary sources:

1. Take the shares outstanding from the cover page of the latest 10-Q or 10-K (SEC EDGAR).
2. Subtract insider and affiliate holdings, found in the beneficial ownership tables (proxy / 10-K) and in Form 4/Form 3 filings.
3. Subtract shares under lock-up (common after an IPO or a recent placement — see the S-1/424B prospectus).
4. Date the result. A float only means something with the date of the source data, because the number moves.

It's manual work, and that's precisely where numbers start to diverge from one source to another.

Why do two sources give different floats?

This is the core problem for a small-cap trader. A displayed float isn't a single truth: it's the result of a calculation, on a date, from specific documents. Four main causes of divergence:

1. Stale data. A source may still show the float from before a recent dilution (ATM, placement, warrant conversion). The number was right yesterday; it isn't today.
2. Different definitions. Some sources remove only insiders, others also remove large institutional holders or shares under lock-up. The word "float" doesn't cover exactly the same thing everywhere.
3. Different source filing. A number taken from the cover page of a dated 10-Q can differ from a number taken from a more recent 424B. Both are "correct" as of their respective dates.
4. Data entry errors. Manual calculation introduces human error, especially after a reverse split or a complex transaction.

Important: this divergence is rare in practice — across a typical basket of tracked small-caps, it affects a handful of tickers, not the majority. But when it happens, it often happens at the worst moment: around a dilution or a gap, exactly when the number matters most.

Where to read the float in SEC filings

The primary sources, all public on SEC EDGAR:

SEC filing	What it tells you
10-Q (quarterly)	Shares outstanding on the cover page, as of a specific recent date.
10-K (annual)	Shares outstanding + public float + beneficial ownership tables.
S-1 (registration)	Capital structure before/after a transaction, lock-ups.
424B (final prospectus)	Details of a recent placement — often the freshest data after a dilution.
8-K (event)	Announcement of material events (placement, reverse split) between reports.
Form 4 / Form 3	Insider holdings and transactions — for the portion to subtract.

Best practice: start from the most recent filing and note the date of every number.

How FloatVerify approaches the float

FloatVerify does this SEC-filing reading work continuously and displays, for each number, its source and its date. When two primary sources give a different float, FloatVerify doesn't silently pick a "winning" number: it shows both and flags the contradiction (the "source split," in amber) — so you decide on facts, not on false certainty.

This isn't a promise of an "exact" or "guaranteed" float: it's a number that is sourced, dated, and shown as is — divergence included when it exists.

Recap

Point	Takeaway
Definition	Shares actually tradable by the public.
Formula	Shares outstanding − insiders/affiliates − lock-up.
Relationship	Float ≤ shares outstanding, always.
Sources	10-Q, 10-K, S-1, 424B, 8-K, Form 4 (SEC EDGAR).
Why it diverges	Stale data, definitions, source filing, data entry errors.
Divergence frequency	Rare, but often at the critical moment.

FAQ

Is float the same thing as shares outstanding? No. Shares outstanding are all issued shares. The float subtracts the restricted shares (insiders, affiliates, lock-up) to keep only those tradable by the public. The float is therefore always less than or equal to shares outstanding.

Where do I find the real float of a ticker? In SEC filings on EDGAR: shares outstanding on the cover page of the latest 10-Q/10-K, then subtract insider holdings (Form 4, beneficial ownership tables) and shares under lock-up (S-1/424B). Always date the number you end up with.

Why do two sites show a different float for the same stock? Most often because one of the numbers is stale (recent dilution not accounted for), or because the two sources don't use the same definition of float, or aren't working from the same SEC filing. It isn't frequent, but it happens mostly around a dilution.

How often does the float change? It changes with every transaction that creates or releases shares: ATM offering, private placement, warrant or convertible conversion, lock-up expiry, reverse split. On an active small-cap, that can be several times per quarter — hence the importance of the date.

What is a "low float"? A small float: few shares available for trading. Mechanically, a given volume represents a larger share of the tradable shares. The calculation is only worth something if the float in the denominator is accurate and dated.

Sources

• U.S. Securities and Exchange Commission — SEC EDGAR (10-Q, 10-K, S-1, S-3, 424B, 8-K, Form 4 filings): sec.gov/edgar
• SEC — definition of "public float" (Form 10-K instructions).

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FloatVerify shows the float, dilution and cash burn of US small-caps, every number sourced and dated — and surfaces divergences between sources ("source split") instead of one falsely certain figure.

Disclaimer: FloatVerify is a data tool, not an investment advisory service. Nothing here is a recommendation to buy or sell. Data, not advice.