Float
The number of shares freely available for public trading, excluding insider-held and restricted shares.
The float is the subset of shares outstanding that actually circulates on the open market. It excludes shares held by company insiders (founders, officers, directors) and shares under lock-up or vesting restrictions.
Float size has a direct impact on trading dynamics. A low float stock with heavy buying pressure can move violently because there are few available shares to absorb demand — this is the fuel behind many short squeezes and momentum runs.
Institutional ownership reports and insider filings let traders estimate real float. When insiders lock up shares after an IPO expire, float expands and can create selling pressure.
On the desk
A company has 100 million shares outstanding but insiders own 60 million under lock-up. The public float is only 40 million. A single large fund buying 4 million shares is absorbing 10% of the tradable supply — enough to move the stock meaningfully.