The IPO lifecycle: from S-1 filing to lockup expiration
An IPO moves from a confidential S-1 to pricing, first trade, analyst initiations about 25 days later and lockup expiry around day 180. Here is what each stage means.
Key takeaways
- An IPO typically moves through a registration filing on Form S-1, a roadshow, pricing the night before trading, and a closing a day or two later.
- Emerging growth companies can submit their S-1 confidentially but must file it publicly at least 15 days before the roadshow begins.
- Underwriters' analysts commonly initiate coverage about 25 days after the IPO, at the end of the prospectus delivery period, often all on the same morning.
- Lockup agreements usually bar insiders and pre-IPO holders from selling for 180 days, and lockup expiration is a well-known date for added supply.
The IPO lifecycle is the sequence of events that takes a private company to a public listing and through its first months as a public company: the registration filing, the roadshow, pricing, the first trade, the end of the research quiet period, the first earnings report, and the lockup expiration. Each stage produces specific filings and news, and several of them, especially analyst initiations and the lockup expiry, are dated events that are known well in advance.
The IPO timeline at a glance
| Stage | Typical timing | Key document or event |
|---|---|---|
| Confidential submission | Months before IPO | Draft registration statement (non-public) |
| Public S-1 filing | At least 15 days before roadshow | Form S-1 on EDGAR |
| Amendments and price range | Weeks before pricing | S-1/A with expected price range and share count |
| Roadshow | About 1 to 2 weeks | Management presents to institutional investors |
| Effectiveness and pricing | Evening before first trade | SEC declares S-1 effective, IPO priced |
| First trade | Next morning | Stock opens on the exchange |
| Final prospectus | Within 2 business days of pricing | 424(b)(4) prospectus filed |
| Closing | Usually 1 to 2 business days after pricing | Shares delivered, company receives cash |
| Greenshoe window | Up to 30 days | Underwriters may buy up to 15% more shares |
| Analyst initiations | About 25 days after IPO | Underwriter research published |
| First earnings report | Next quarter end | First 10-Q or 10-K as a public company |
| Lockup expiration | Usually 180 days | Pre-IPO holders free to sell |
Before the IPO: registration and the S-1
A company going public in the US registers its shares with the SEC, usually on Form S-1 (foreign private issuers use Form F-1). The S-1 contains the prospectus: business description, risk factors, audited financial statements, management's discussion and analysis, executive pay, principal shareholders, and the use of proceeds. The guide on Form S-1 and IPO filings walks through it section by section.
Confidential submission. Emerging growth companies (EGCs), generally those with less than about $1.235 billion in annual revenue, can submit a draft registration statement privately to the SEC for review. Since 2017, the SEC has extended confidential review to most other IPO issuers as well. The company must file publicly at least 15 days before the roadshow starts, which is when most investors first see the numbers.
The pre-IPO quiet period. Under the Securities Act, companies face limits on promotional communications before and during registration, often called "gun-jumping" rules. That is why IPO candidates tend to avoid publicity in the run-up to listing. EGCs can "test the waters" with qualified institutional buyers and institutional accredited investors, and since 2019 all issuers may do so.
Pricing, first trade and closing
During the roadshow, underwriters collect indications of interest from institutional investors (the "book"). An S-1/A sets an expected price range. On pricing night, after the SEC declares the registration statement effective, the company and lead underwriters agree on the final price and share count based on demand. The price can land within, above or below the range, and the deal size can change.
The stock usually begins trading the next morning. The opening trade often happens well after 9:30 a.m. Eastern, because the exchange runs a special IPO opening auction once buy and sell orders are balanced. The gap between the IPO price and the opening price is the "pop" (or drop).
The final prospectus is filed under Rule 424(b)(4). The deal closes, with the company receiving the proceeds, usually one or two business days after pricing.
Greenshoe (over-allotment option). Underwriters typically sell up to 15% more shares than the base deal and hold an option to buy those extra shares from the company for up to 30 days. If the stock trades below the IPO price, underwriters can instead cover by buying in the market, which supports the price. This stabilization activity is permitted under SEC Regulation M.
After the IPO: the research quiet period
Once the stock trades, research from the banks that underwrote the deal is restricted for a period. FINRA Rule 2241 sets a 10-day quiet period after an IPO for research from participating underwriters, and the JOBS Act removed some restrictions for EGCs. In practice, underwriters' analysts commonly wait about 25 days, matching the prospectus delivery period for exchange-listed IPOs, and then publish initiations together.
This "quiet period expiration" is a predictable news day. Underwriter initiations skew positive because the banks chose to take the company public. The reaction depends on how far the stock has already moved since the IPO. See analyst upgrades and downgrades for how to read initiations.
The first earnings report
A newly public company files its first 10-Q or 10-K for the first period ending after the IPO and usually hosts its first earnings call. This is the first test of whether results match the story told on the roadshow, and first-quarter guidance is closely watched. Newly public companies often have limited trading history, so reactions to the first report can be large. See how to read an earnings report.
Lockup expiration
A lockup agreement is a contract between the underwriters and pre-IPO holders (founders, employees, venture capital and private equity funds) that bars them from selling shares for a set period after the IPO, most commonly 180 days. Terms are disclosed in the S-1 under "Shares Eligible for Future Sale" and "Underwriting."
Many lockups now include variations:
- Early release of a portion of shares if the stock trades above a set premium to the IPO price for a number of days, or after the first earnings release.
- Staggered expiry, with portions released at different dates.
- Underwriter waivers, which can release shares early for a follow-on offering.
When a lockup expires, a large share count may become eligible for sale. Not all of it will be sold, and the date is public, so the market can anticipate it. Still, lockup expirations are often associated with increased volume and selling pressure, particularly when pre-IPO holders have large gains. Insiders who are affiliates still sell under Rule 144 limits and may file a Form 144 before selling.
Worked example: a hypothetical IPO calendar
Acme Corp (ticker ACME) prices its IPO on Wednesday, March 4, 2026, at $20.00, the top of its $17 to $20 range, selling 10 million shares. The base deal raises $200 million. Underwriters have a 30-day option on 1.5 million more shares (15%).
| Date | Event | What to check |
|---|---|---|
| Mar 4 (evening) | Pricing | Price vs range, upsized or not |
| Mar 5 | First trade, opens at $26.00 | Opening pop, volume |
| Mar 6 | 424(b)(4) final prospectus | Final share count, lockup terms |
| Mar 6 or 9 | Closing | Company receives proceeds |
| By Apr 3 | Greenshoe deadline | Whether underwriters exercised |
| About Mar 30 | Analyst initiations from underwriters | Ratings and price targets |
| May | First earnings as a public company | Results vs roadshow story, guidance |
| Aug 31 | 180-day lockup expiration | Shares unlocked, Form 144 filings |
The S-1 might say 60 million shares are subject to lockup, compared with 10 million sold in the IPO. That ratio, six times the public float, is the kind of number investors note ahead of the expiry date.
Other routes to market
- Direct listing. Existing shareholders sell directly on the exchange without underwriters or a lockup in the traditional sense. The NYSE and Nasdaq also allow primary direct listings, where the company raises capital.
- SPAC merger. A special purpose acquisition company that is already listed merges with a private company. Disclosure comes through a proxy or S-4 rather than an S-1, and lockups and redemptions work differently.
- Uplisting. A company already trading over the counter moves to a national exchange, often with a concurrent offering. See stock exchanges explained.
How to follow IPOs on Quantisnow
- The IPO calendar lists upcoming and recent IPOs, and the S-1 category collects registration statements and amendments as they are filed.
- The offerings feed shows pricing announcements and follow-on deals, and coverage initiated catches analyst initiations at quiet period expiry.
- Company pages at the pattern /company/ACME collect filings, news and data for each new listing. Use alerts to be notified of the first earnings report and Form 144 filings.
FAQ
What is the IPO quiet period?
The term is used for two periods. Before the IPO, Securities Act rules limit promotional communications by the company. After the IPO, research from the underwriting banks is restricted, and underwriters' analysts commonly initiate coverage about 25 days after the offering.
How long is an IPO lockup period?
Most IPO lockups last 180 days from the offering, though some are shorter or include early release provisions tied to stock price or the first earnings release. The terms are disclosed in the S-1 and the final prospectus.
What happens when an IPO lockup expires?
When a lockup expires, founders, employees and pre-IPO investors become free to sell shares, subject to securities rules such as Rule 144 for affiliates. The extra potential supply is often associated with higher volume and selling pressure around the date.
What is a greenshoe option?
A greenshoe, or over-allotment option, lets underwriters buy up to 15% more shares from the company, usually within 30 days of the IPO. It gives underwriters flexibility to support the stock price if it falls below the offer price.
Why does an IPO stock open later than 9:30 a.m.?
The listing exchange runs a special opening auction for the IPO and waits until buy and sell interest is balanced at an opening price. This can take from minutes to a few hours after the regular open.
What is the difference between the S-1 and the 424(b)(4)?
The S-1 is the registration statement, including the preliminary prospectus with a price range. The 424(b)(4) is the final prospectus filed after pricing, with the actual offering price and final share count.