Which of the following is not considered a partial substitute for the sale of 100% ownership of a company?

The initial public offering (IPO) is considered a method for a company to raise capital by offering shares of its stock to the public for the first time. While an IPO can lead to a change in ownership structure by allowing shareholders to buy and sell shares, it does not directly involve the sale of a company's assets or its entire ownership. An IPO enables the original owners to retain control over the company while also gaining access to public investment.

In contrast, methods such as joint ventures, equity swaps, and the sale of assets can be more closely related to alternatives for divesting ownership or interests in a company. A joint venture involves partnering with another company, which may lead to shared ownership, while equity swaps may involve exchanging ownership stakes in different companies. The sale of assets directly impacts the ownership structure, as it entails the transfer of specific parts of a company or its overall value to another entity.

Thus, the key distinction here is that an IPO does not equate to a partial substitute for the direct ownership transfer that occurs in a sale of 100% ownership, hence making it the correct answer.