Share buybacks

What this actually is

A company buying its own shares, which reduces the share count and mechanically raises earnings per share. It is the largest single source of demand for US equities — larger than all fund inflows combined.

Why it matters to a person

It matters most for what happens when it stops. Companies are barred from buying in the weeks before earnings, which removes the market's biggest buyer for roughly five weeks a quarter — one of the most reliable seasonal patterns in the calendar.

For scale

Over a trillion dollars a year in recent years. A 1% excise tax was introduced in 2023; the effect on volumes was minimal, which tells you the tax rate needed to change behaviour is far higher.

How to read a release

The mechanism

The largest single source of equity demand; the five weeks before earnings when it switches off are seasonally weak.

What to watch: S&P 500 quarterly buyback total; blackout windows. Arrives quarterly; the effect typically lasts months. Impact tier 2 — Directional: Moves the index for days or weeks. Scheduled data releases, policy decisions, global spillovers, and the prices of money and energy. This is the tier most professional attention is spent on.

Primary source — spglobal.com ↗