Free Float

Free float (also called "float" in trading contexts) refers to the number of a company's shares that are freely available for trading by the general public. It excludes shares that are locked up, held by insiders under restriction agreements, owned by controlling shareholders with no intention to sell, or held by government entities as part of a strategic stake. Free float is a subset of total shares outstanding.

Free Float vs Shares Outstanding

Shares outstanding is the total count of all issued shares — including those held by founders, executives, employees (vested stock), institutional investors, and the public. Free float subtracts the shares that are effectively illiquid: insider holdings typically restricted by lockup agreements or trading windows, major institutional positions that are strategic rather than speculative, and treasury shares held by the company itself. For a large-cap company like Microsoft, free float is close to total shares outstanding (few restrictions on the vast majority of shares). For an early-stage company with significant founder ownership and restricted stock, free float might be only 20–30% of outstanding shares.

Why Free Float Matters for Volatility

Free float determines the effective supply of shares available at any moment. A company with a small free float (few shares available for trading) experiences much greater price volatility per dollar of trading volume than one with a large float. When a catalyst fires on a low-float stock, the same dollar volume of buying activity that would move a large-float stock 2% can move a low-float stock 15–30%. This amplification effect is why small-cap, low-float stocks are disproportionately represented in the largest intraday catalyst moves.

Free Float and Short Squeezes

The combination of high short interest and low free float creates the conditions for short squeezes. If a stock's free float is 5 million shares and 3 million shares are sold short (60% short interest), a positive catalyst that triggers short covering creates demand for 3 million shares against a backdrop of only 5 million available. The resulting price compression — forced buyers competing for a limited supply — can produce moves of 50–200% in hours. The GameStop event in 2021 is the canonical modern example.

Free Float in TradeAI News Scoring

Free float is one of the inputs to the TMS scoring calibration. For a given catalyst event, the expected move magnitude is adjusted based on the target company's float — the same FDA approval on a 500k-share float biotech should produce a much larger percentage move than on a 50-million-share float company. This calibration helps prevent the system from under-scoring genuine catalyst events on small-float names while over-scoring on large-float names.