There are many employee-owned cooperatives, some of which were once companies owned by one or more investors or the original owners. Though that is where the employees are the stockholders.
There are also organizations which have no investors, such as foundations and non-profit organizations and churches etc.
A for-profit corporation which bought out its investors might tend to become a non-profit organization, though I suppose in theory there could be a for-profit corporation with no investors – maybe it’s purpose is to destroy capitalism as we know it, by trying to own everything.