Liquidity Event

Founders start off owning the entire company.
Then they convince VCs to buy some of it, and they use that money to pay themselves salaries.
Then the VCs convince either retail investors or a megacorporation to buy the company, and that's a liquidity event.

This sounds like a pyramid scheme, but trust me, it isn't.

Employees can't do anything with their stock options until a liquidity event.