IPOs explained: what if you had bought at the IPO?

A company owned so far by founders, staff or investors offers shares to everyone for the first time. It needs a prospectus: a long document on the business, the numbers and the risks. In Germany BaFin approves it. Important: BaFin checks that the prospectus is complete, consistent and understandable. It does not check whether the statements are true or whether the stock is a good deal. The company is liable for that.

Most offers use book building: banks sound out large investors and set a price range. During the subscription period they collect buy orders. Then the offer price is fixed and the stock trades on the exchange for the first time.

You need an ordinary brokerage account. During the subscription period you place a buy order with a limit: how many shares you want and the most you will pay per share. For large IPOs, often only the banks in the syndicate offer subscriptions. Deutsche Börse also offers subscription via the Frankfurt venue, which many brokers support.

If the offer is oversubscribed, meaning more people want to buy than there are shares, the shares are allocated. Private investors then often receive only a few or none. You only pay for allocated shares; open orders lapse before trading starts. If you get nothing, you can buy on the exchange from the first trading day, but at the market price, not the offer price.

The offer price only applies to allocated shares. The first market price forms freely and can differ a lot. An example from this year: Vincorion was placed at €17.00 in March 2026; the first price in Frankfurt was €19.30. Anyone buying after the start already paid more. It can go the other way too: a stock can drop below its offer price on day one.

Months later there can be another bump. Large shareholders may not sell for a while because of a lock-up. When it ends, many shares can come to market at once. The SpaceX prospectus sets several release dates, the last one after 180 days.

The table above covers stocks from our list that went public within our data window: what would 1,000 (in euros or dollars) be worth today if invested at the close of the listing month? We deliberately use the first monthly close, not the offer price, because private investors often could not get the offer price, and our prices are adjusted for stock splits. Dividends and currency moves are not included.

An IPO is not a discount. Sellers and banks set the price so it works for them, and demand is highest when there is a lot of media buzz. A young listed company also has little market history: no price record through bad years, often few published quarterly reports.

If an IPO interests you, read the risk factors in the prospectus, set a limit and invest only a small part of your money. And check whether you already own it: anyone holding a global ETF such as the MSCI World has held a tiny slice of SpaceX since July 2026.