How an IPO Works, From SEC Filing to Public Trading

An IPO has an offering price, but that is not necessarily the price an individual investor will pay once the stock begins trading publicly. The offering price results from a process involving the company and its underwriters. After trading starts, the available supply of shares and market demand can push the price higher or lower.

That distinction helps explain why a dramatic first-day move is not, by itself, proof that the market has discovered a company’s “correct” value. Pricing choices, restricted supply and lockups can all influence early trading.

The path from filing to trading

A company generally begins the registration process by filing a registration statement with the SEC, typically using Form S-1. A central part of that filing is the prospectus, the offering document provided to prospective investors.

The prospectus describes the company, the IPO’s terms, its business, financial condition, management and other matters relevant to an investment decision. It also discusses the underwriting agreement and the factors considered in setting the offering price, usually under “Underwriting” or “Plan of Distribution.”

The broad sequence looks like this:

For participating firms subject to its public-offering rules, FINRA reviews documents and underwriting arrangements alongside the SEC registration process. Firms generally must submit required public-offering documents no later than three business days after filing or submitting them to the SEC. A firm must receive a No Objections letter before participating in a distribution covered by the filing requirement.

These processes address different parts of an offering. The registration statement supplies company and securities disclosures, while FINRA’s review focuses on whether participating firms’ underwriting terms, compensation arrangements and relevant conflicts comply with its rules.

What underwriters do—and how the IPO price is set

Underwriters are investment banks that manage and sell the IPO for the company. Before the offering becomes effective, they typically obtain indications of interest from prospective investors and use that information to recommend a price to the issuer.

The issuer ultimately determines the IPO price through a process involving the underwriters. That price reflects market conditions, analysis and negotiation rather than a fixed formula or an independent market vote. The interests involved can also compete: the company and underwriters must agree on terms, while underwriters want a price that appeals to the client-investors receiving shares.

Pricing the shares below what investors are willing to pay can create a discount for initial investors, increase demand and help the underwriters sell the available shares. It may also contribute to a first-day increase. But a large jump means the initial allocation recipients and later public-market buyers encountered very different prices.

Why the first trading price can be misleading

Early public trading can involve only a fraction of the company’s outstanding shares. The shares available on the first day are generally shares sold in the IPO rather than all shares owned by founders, employees and early investors.

Some other holdings may be restricted securities that cannot be resold without registration except under specified circumstances. Existing shareholders may also have agreed not to sell under lock-up agreements. Underwriter policies can further reduce supply by discouraging “flipping,” meaning the immediate resale of allocated IPO shares. Although flipping alone is not prohibited under federal securities laws, underwriters may decline future allocations to customers who previously flipped shares.

When a sought-after IPO has high demand but relatively few tradable shares, that limited supply can drive the public-market price sharply higher. A first-day surge can therefore reflect a tight trading supply as well as investor enthusiasm. It does not necessarily mean every outstanding share could have been sold at that price.

This resolves a common misunderstanding: registration and underwriting produce the offering and its disclosures, but they do not produce a permanent valuation. Once trading begins, the quoted price applies to shares currently changing hands under the supply conditions prevailing at that moment.

Lockups delay supply; they do not remove it

A lock-up agreement is a shareholder’s commitment not to sell shares for a specified period. IPO lockups are typically 180 days under the arrangements described in the investor bulletin, although the applicable agreement determines the actual restriction.

Shares outstanding but unavailable for trading at the IPO are sometimes called the “market overhang.” That overhang matters because expiration of a lockup can allow founders, employees and early investors to sell shares that were previously unavailable. Early shareholders may view the IPO as an opportunity eventually to realize gains by selling to the public.

A lockup does not create or cancel shares. It temporarily limits which existing shares may enter the market. When an agreement expires, the tradable supply may rise, and the share price may decline if many shares become available for sale at once. A decline is not guaranteed; the mechanism is a change in potential supply, not a predetermined price outcome.

A prospectus-based way to evaluate the risks

IPO risk is easier to analyze when the offering price, public trading price and future share supply are treated as separate questions:

1. What exactly is being offered? The prospectus explains the securities and the IPO terms, rather than merely presenting the company’s public story.
2. How was the offering priced? The underwriting section can show the factors behind the price and the terms between the issuer and underwriters.
3. Which price applies to the investor? An allocation at the offering price and a purchase after public trading starts can produce very different results.
4. How constrained is early supply? Restricted shares, lockups and anti-flipping policies can leave relatively few shares available for immediate trading.
5. When could supply expand? Lockup expiration may let a substantial group of existing shareholders sell, creating a risk that was not visible in the first day’s limited trading.

The prospectus cannot determine what the stock will do after listing. Its practical value is that it separates disclosed information about the business and offering from the excitement—and sometimes unusually limited supply—surrounding the first days of trading.

Sources

1. Investor Bulletin: Investing in an IPO — sec.gov
2. Public Offerings | FINRA.org — finra.org
3. Updated Investor Bulletin: Investing in an IPO — investor.gov
4. Investor Bulletin: Investing in an IPO — sec.gov