U.S. IPO Lock-Ups: Dates, Terms and Filings
Understand IPO dates, lock-up terms and the prospectus sections that explain when restricted shares may become eligible for sale.
Key IPO and lock-up dates
An IPO lock-up is an agreement restricting share sales by specified holders for a set period. The prospectus and later filings identify the covered holders, dates and exceptions.
Filing the registration statement
Forms S-1, F-1 and S-11 describe a proposed offering. A filing does not establish that the registration is effective or that a first trading date is set. Terms can change, and SEC review is not an endorsement of the investment.
Setting the offer price
The final offer price and number of shares help describe the size of the offering. Offered shares, shares outstanding and shares subject to a lock-up measure different things and cannot be used interchangeably.
Trading begins and the offering closes
The first trading day and closing day may differ. To work out a lock-up expiry date, find the start date specified in the agreement. Do not choose either day without checking the terms.
Checking the lock-up expiry
Find the covered holders, start date, duration and early-release clauses, then check later amendments. One IPO can have several release windows. A quiet period concerns communications or research publication and is separate from restrictions on share sales.
What to read in a prospectus
| Focus | Prospectus section | What to look for |
|---|---|---|
| Business and customers | Business / Prospectus Summary | Revenue sources, key customers and dependence on a small number of customers or contracts. |
| Financial performance | Financial Statements / MD&A | Revenue, profit or loss, cash flow and debt. Check the reporting period and the base period for comparisons. |
| Use of proceeds and dilution | Use of Proceeds / Dilution / Capitalization | How the money will be used, any sales by existing shareholders and the effect of new shares on ownership percentages. |
| Shareholders and potential supply | Principal Stockholders / Shares Eligible for Future Sale | Major holders, share classes and the holders and shares covered by each release window. |
| Lock-up terms | Underwriting / Lock-Up Agreements | The start date, expiry conditions, early-release authority, exceptions and later amendments. |
| Risk factors | Risk Factors | Issuer-specific risks, including customer concentration, related-party transactions, continuing losses and regulation. |
Lock-up questions
How long does an IPO lock-up last?
Investor.gov describes 180 days as a common term. Agreements vary, so check the start date, expiry conditions, early-release clauses and later amendments.
Why do websites show different expiry dates?
They may use different start dates, omit an amendment or describe different holders. Counting 180 days can also give a different result from counting six calendar months. Compare the original agreement and later disclosures.
What time do shares become eligible for sale?
Use the time and time zone stated in the source. A date alone does not establish midnight, pre-market or market open. Confirm processing arrangements with the issuer, transfer agent or broker.
Can I sell as soon as the lock-up expires?
Other conditions may still apply, including insider-trading policies, material nonpublic information, Rule 144, vesting, exercise, settlement and broker processing. Check the requirements that apply to your holding before trading.
Can a lock-up end early or be extended?
An agreement may allow a waiver, an early release or a conditional window. Check amendments and issuer announcements. A date saved in your calendar does not establish that an exception applies.
Why is the share count unknown?
The date may be supported while the relevant share count still needs checking. Unknown does not mean zero, and the number of shares offered in an IPO cannot substitute for the shares covered by a lock-up.
Will the price fall when the lock-up expires?
The end of a restriction does not establish that holders will sell. Share counts, free float and liquidity provide context but do not determine the direction of the share price.
What should I do if I cannot find a record?
Try a wider date range and check issuer and regulatory filings. Coverage is still expanding, so an absent record does not establish that no restriction exists. Where monitoring is enabled, a stock can be followed before its date is known.
Will a saved calendar event update automatically?
A CSV or ICS export reflects the record at export time; imported events may not update automatically. Enabled email reminders require confirmation. Stock monitoring processes verified changes after a successful source check.
Dates, sources and coverage
Start with the original filing, then check the date, covered holders and terms. IPO Lock retains sources, evidence summaries and verification times. Expected dates stay labeled, and conflicting or unsupported information stays under review. A verification time is not a filing date or quote time, and recorded events do not establish full-market coverage.
SEC: IPO lock-up agreementsGeneral research guidance only. This is not individualized legal, tax, investment or trading clearance.
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