A company launches an IPO (Initial Public Offering) when it has not previously quoted on any market. An IPO is the first step for the company to go public, that is, for the shares of that company to begin trading on the stock market.
Just before the IPO, there is a pre-IPO placement, which is a sale of large packages of shares to private investors, especially institutional investors, private equity or investment funds. The price of the shares in this prior placement is usually lower than the reference price for the IPO.
When the company begins to quote on the stock market, its shares use this reference price, although this price is not guaranteed -its value will depend on the existing demand in the market. The higher the demand, the higher the price will increase.
Therefore, in some cases, in order to prevent investors from immediately selling the shares they have bought and to prevent the price from falling, they sign a lock-up commitment, so that they are committed to keep their shares for a certain period of time.