You ask a great question. There are a number of reasons that companies go public: get liquidity for owners, raise additional capital in public markets, have public stock as a currency for acquisitions, etc.
In the situation you describe, you wouldn't raise any additional capital if you're only selling shares you already own in the public offering. Only you, the owner, would receive capital from the IPO.
In most IPOs, however, additional shares are issued to raise additional capital. Let's say your 100% ownership is 10 million shares ($10 a piece). In an IPO, you want to raise $25 million. You would issue 2.5 million additional shares in the IPO at $10 a share to receive $25 million when they are issued. You could also sell some of your own shares, but that money would come directly to you rather than into the company.
The $25 million raised would come in as cash to the company and would be used to create more value for the company. Here is more detail on how the process plays out:
Experience with public offerings.
· 7 years ago