Free float is the portion of a company's shares that's actually available for trading on the market — as opposed to held by founders, the state, or strategic blocks. A small free float means most of the shares never move; transactions hit only the visible slice and prices can swing more on small order flow.
The SGBV's listing rules set minimum free float by compartment. Principal requires 20% or so; Croissance and PME allow lower. When you read a listing disclosure, the free-float number is often the first thing to check — it tells you whether you're looking at a real market for the stock or at a sliver of one.
The AYRADE card shows 20% free float at IPO. That's exactly the Croissance compartment minimum.