An Initial public offering (IPO) marks the first time a company sells shares to the public. It’s also known as ‘listing’ or ‘floating’ on the public markets – which in the UK means a ‘new issue’ on the London Stock Exchange.If you’re lucky enough to have a turnover of more than £5m (or you’ve reached unicorn status!) you might entertain the idea of an initial public offering (IPO).In a UK IPO, you can sell shares in your business via three public markets operated by the London Stock Exchange: Main Market (Premium) – for established companies (home of the FTSE 100 and 250 indices) Main Market (High Growth Segment) – for high-growth companies that in time want to become Premium listed companies Alternative Investment Market (AIM) – for smaller, growing businesses looking to scale up to mature businesses