Some founders seed their companies with their personal capital in the early days. There are a variety of ways to handle this, with a loan from the founder as a shareholder being the one I’ve seen most. When a founder plans to grow their company quickly and raise venture capital, they have another option: they can classify their capital as an investment in the company. The easiest way to do this is through a convertible note or simple agreement for future equity (SAFE).
Why would a founder want to do this? For many reasons. One is that it helps to separate sweat equity from financial equity. If a founder must leave the company for some reason and their equity as a founder doesn’t vest, they still have their financial equity. The founder will own a percentage of the company based on their investment, regardless of what happens with the equity tied to their employment.
There are other benefits too, such as owning—for the financial equity—preferred equity versus common equity.