Nasdaq rewrote the playbook for SpaceX. Only a small slice of SpaceX shares was initially available for public trading. The rest is held by insiders, employees, early investors, and other locked-up holders who are not yet free to sell most of their stock into the market. That tradable slice is often called the float. In plain English, it is the stock that investors can actually buy and sell. The chart shows the timing issue. Index-fund buying arrives first. More tradable shares arrive later as restrictions ...