Definition

Weighted-average shares

The share count used to compute earnings per share: shares outstanding averaged over the period, weighted by how long each tranche was out. Buybacks and issuances mid-year move it gradually rather than all at once, which is why EPS math never uses the point-in-time count on the cover page.

Formula

EPS = Net income ÷ Weighted-average shares (diluted adds in-the-money awards)

Drivers — what actually moves it

Buybacks: repurchases shrink the average over time — the per-share lever that needs no earnings growth.
Issuance & awards: equity compensation and raises add shares; the diluted count includes awards not yet exercised.

Where to find it in the filing

Income statement (per-share data) + the EPS footnote. 10-K Item 8 — basic and diluted weighted-average counts beneath EPS; the footnote reconciles the two.

XBRL concepts Echelon grounds to: WeightedAverageNumberOfSharesOutstandingBasic · WeightedAverageNumberOfDilutedSharesOutstanding

Prove it on a model

Accretion / dilution on AAPL’s filing“Is this deal accretive or dilutive?”

Sector caveats — where this breaks

The cover-page share count is a different number for a different purpose — mixing the two misstates per-share math.

Diluted EPS Market capitalization

Educational use only — not investment advice. Figures come from public SEC filings; Echelon teaches you to analyze data, it never recommends buying or selling any security.