先来看一下Investopedia作出的相关解释：

“Flotation is the process of converting a private company into a public company by issuing shares available for the public to purchase. It allows companies to obtain financing externally instead of using retained earnings to fund new projects or expansion. The term "flotation" is commonly used in the United Kingdom, whereas the term "going public" is more widely used in the United States.

Flotation requires careful consideration regarding timing, company structure, the company's ability to withstand public scrutiny, increased regulatory compliance costs, and the time needed to execute the flotation and attract new investors. While flotation provides access to new sources of capital, the extra expenses associated with issuing new stock must be accounted for when considering the switch from a private to a public company.

Companies in mature phases of growth may need additional funding for various reasons including expansion, inventory, research and development, and new equipment. For this reason, the time and monetary costs of becoming a company that is traded publicly are often deemed worth it.

When a company decides to pursue flotation, they typically enlist an investment bank as an underwriter. The underwriting investment bank typically leads the process for conducting an IPO and helps the company determine the amount of money it seeks to raise from the public market issuance.

There are flotation costs associated with issuing new equity, or newly issued common stock. These include costs such as investment banking and legal fees, accounting and audit fees, and fees paid to a stock exchange to list the company's shares.”

从上述描述可看出，“flotation”指的是通过向公众发行股份将私人公司变为公众公司，此术语常在英国使用，而美国更常使用的是“going public”，因此“flotation”与“going public”同义，即表示“上市发行”。

发行证券需要仔细考量以下因素：时机、公司结构、公司承受公众监督的能力、较高的合规成本、发行证券和吸引新投资人所需的时间。尽管发行股票是获得外部融资的机会，但相关额外费用仍须考虑在内。

公司在成熟期需要额外融资可能基于以下原因：业务扩展、研发、引进新设备等。因此，发行证券花费的时间和成本通常被视为是有必要的。

发行成本通常包括投资银行和法律费用、会计和审计费用、向证券交易所缴纳的股票上市费用。