What is a 424B prospectus? SEC final prospectus (2026)
A 424B prospectus is the version of a prospectus a company files with the US Securities and Exchange Commission after its registration statement is already on file. Once an S-1, S-3, or F-1 is declared effective, the company does not amend it to add pricing. Instead it files a 424B prospectus under Rule 424(b) with the final or supplemental terms. It is the priced document an investor actually receives, which is why the 424B prospectus is where you find the numbers that were blank in the earlier filing. This page explains it, and it is not investment advice.
Definition
A 424B prospectus
is the prospectus a company files with the SEC under Rule 424(b) after its registration statement. It supplies the final terms, mainly pricing, without amending the registration statement, and it is the version delivered to investors. Source: SEC, Rule 424(b).
What does a 424B prospectus do?
Rule 424 governs how a prospectus reaches investors once a registration statement has been filed. The 424(b) path lets a company lock in details that were not final at the time the registration statement was declared effective, above all the offering price, without going back to amend the registration statement. That keeps the mechanics clean: the SEC reviews the framework, then the priced prospectus follows.
2 business days
General window under Rule 424(b) to file the prospectus after the price is set or it is first used
Source: SEC, Rule 424(b)
The 424B subtypes
On EDGAR you will see the form written with a number that points to the paragraph of Rule 424(b) it is filed under:
- 424B1 and 424B4: a final prospectus carrying pricing after an offering is declared effective, common at the close of an IPO
- 424B3: a prospectus filed under Rule 424(b)(3)
- 424B5: a prospectus supplement for a shelf offering, used to price a takedown from a shelf registration
The suffix is a filing mechanic, not a difference in what the document is for. All of them deliver the current, usable prospectus to the market.
How it fits the registration process
The 424B is the last step, not the first. A company files an S-1 for a first-time registration or an S-3 for a short-form shelf, the SEC reviews and declares it effective, and then the 424B prospectus follows with the final terms. India runs a parallel idea for IPOs, where the near-final offer document is the red herring prospectus. To pull any of these from the regulator's own system, see how to search SEC EDGAR.
Flock reads primary filings, keeps each one dated, and links back to its SEC source. What the data means for you is your call to make.
Frequently asked questions
What is a 424B prospectus?
A 424B prospectus is the prospectus a company files with the SEC under Rule 424(b) after its registration statement, such as an S-1 or S-3, is on file. It carries the final terms, including pricing, without amending the registration statement itself. It is the version investors actually receive. Source: SEC, Rule 424(b).
What are the 424B subtypes?
Common forms include 424B1 and 424B4 for a final prospectus with pricing after an offering is declared effective, 424B3 for a prospectus filed under Rule 424(b)(3), and 424B5 for a prospectus supplement in a shelf offering. The number after 424B indicates which paragraph of Rule 424(b) the filing is made under. Source: SEC EDGAR.
When must a 424B prospectus be filed?
Under Rule 424(b), the prospectus is generally filed within two business days of the earlier of the date the offering price is determined or the date it is first used. This lets the company add final pricing after the SEC declares the registration statement effective. Source: SEC, Rule 424(b).
How is a 424B different from an S-1?
An S-1 is the registration statement that gets the SEC's review and is declared effective. A 424B is the prospectus filed afterward that fills in the final terms, mainly pricing. The S-1 is the framework; the 424B is the priced, deliverable version. Source: SEC EDGAR.
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Disclosures shown are public regulatory filings. Data may be delayed or incomplete. Smart-money entities may no longer hold positions shown. Not investment advice.