The IPO Ecosystem

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United States · IPO Ecosystem

The IPO Ecosystem

An IPO is carried out by a fixed cast of parties: the company, the firms that distribute its shares, the professionals who certify parts of the filing, the market institutions that register and police those firms, and the investors who buy. U.S. law names most of these roles directly, and defines them by function rather than by title.

Each section answers one question, with every fact mapped to a named primary authority and linked for verification.

Who are the participants in a U.S. IPO, and what fixes each party's role?

The parties to an IPO fall into three groups, and federal statute names most of them. The Securities Act of 1933 defines the two principals to the offering — the 'issuer' in Section 2(a)(4) and the 'underwriter' in Section 2(a)(11) — and Section 6(a) names the individuals who must sign the registration statement. The Securities Exchange Act of 1934 defines the market institutions built around them, including 'exchange' (Section 3(a)(1)), 'self-regulatory organization' (Section 3(a)(26)) and 'transfer agent' (Section 3(a)(25)). The professionals who certify parts of the filing — the accountant and counsel — are reached through Section 7(a) of the Securities Act and the SEC's exhibit and consent rules.

The practical consequence of defining roles this way is that a party's title does not settle its legal position. Section 2(a)(11) attaches the underwriter label to conduct — purchasing from an issuer with a view to distribution, or participating in the undertaking — whatever the party calls itself. Section 7(a) fixes the certifying professionals by a different test: it reaches 'any accountant, engineer, or appraiser, or any person whose profession gives authority to a statement made by him' who is 'named as having prepared or certified any part of the registration statement,' so the consent duty follows the profession and the naming rather than the party's billing in the deal. Three categories result: the deal parties (issuer, its signing officers and directors, the underwriters and their counsel), the certifying professionals (the independent registered public accounting firm; issuer's counsel), and the institutions and service providers (the SEC, the listing exchange, FINRA, the transfer agent, the EDGAR filing agent) — with the investors as the counterparties to every sale. What each party does at each step of the process is mapped on the IPO Lifecycle page of the IPO Center; this page maps who they are and what authority defines each one.

Source: Securities Act of 1933, Sections 2(a)(4), 2(a)(11), 6(a) and 7(a) — U.S. GPO compilation (govinfo); Securities Exchange Act of 1934, Section 3(a) ↗

Who is the 'issuer,' and which people sign for it?

Under Section 2(a)(4) of the Securities Act, 'the term ‘issuer’ means every person who issues or proposes to issue any security' — in an IPO, the company whose shares are registered. Section 6(a) names the people who must sign: at least one copy of the registration statement 'shall be signed by each issuer, its principal executive officer or officers, its principal financial officer, its comptroller or principal accounting officer, and the majority of its board of directors or persons performing similar functions,' and, where the issuer is a foreign or Territorial person, by its duly authorized representative in the United States.

Section 6(a) also sets the evidentiary rules around those signatures: signatures written on the registration statement 'shall be presumed to have been so written by authority of the person whose signature is so affixed,' the burden of proof falls on the party denying that authority, and 'the affixing of any signature without the authority of the purported signer shall constitute a violation of this title.' The issuer's position is also the strictest one in the statute: Section 11(b) opens 'Notwithstanding the provisions of subsection (a) no person, other than the issuer, shall be liable as provided therein who shall sustain the burden of proof' of the listed defenses — the defenses are unavailable to the issuer itself, a point developed on the IPO Due Diligence page of the IPO Center. What the registration statement must disclose about these officers and directors is covered on the IPO Leadership page.

Source: Securities Act of 1933, Sections 2(a)(4), 6(a) and 11(b) — U.S. GPO compilation (govinfo) ↗

What legally makes a party an 'underwriter'?

Status, not title. Section 2(a)(11) of the Securities Act defines an 'underwriter' as 'any person who has purchased from an issuer with a view to, or offers or sells for an issuer in connection with, the distribution of any security, or participates or has a direct or indirect participation in any such undertaking, or participates or has a participation in the direct or indirect underwriting of any such undertaking.' Each of the four limbs is conduct-based: purchasing with a view to distribution, offering or selling for the issuer in the distribution, participating in the undertaking, or participating in the underwriting of it.

The definition carries one carve-out and one expansion. The carve-out: the term 'shall not include a person whose interest is limited to a commission from an underwriter or dealer not in excess of the usual and customary distributors’ or sellers’ commission' — which is why an ordinary selling-group dealer taking a customary concession is not, on that basis alone, an underwriter. The expansion: 'As used in this paragraph the term ‘issuer’ shall include, in addition to an issuer, any person directly or indirectly controlling or controlled by the issuer, or any person under direct or indirect common control with the issuer,' so a person distributing for a control person can be an underwriter. The status has a direct consequence under Section 11(a)(5), which makes 'every underwriter with respect to such security' suable on the registration statement. How the underwriters organize among themselves, and how the spread is split, is covered on the Underwriting Syndicates page of the IPO Center.

Source: Securities Act of 1933, Sections 2(a)(11) and 11(a)(5) — U.S. GPO compilation (govinfo) ↗

What regulatory status must the underwriting firms themselves hold?

They must be registered broker-dealers, and in practice FINRA members. Section 15(a)(1) of the Securities Exchange Act makes it unlawful for a broker or dealer (other than one whose business is exclusively intrastate and that uses no facility of a national securities exchange) to use the mails or any means or instrumentality of interstate commerce to effect transactions in, or to induce or attempt to induce the purchase or sale of, any security — other than an exempted security or commercial paper, bankers' acceptances, or commercial bills — unless registered in accordance with Section 15(b). Section 15(b)(8) then makes it unlawful for a registered broker or dealer to effect any transaction in any security 'unless such broker or dealer is a member of a securities association registered pursuant to section 15A of this title or effects transactions in securities solely on a national securities exchange of which it is a member.'

The two labels are defined in Section 3(a) of the Exchange Act: a 'broker' is 'any person engaged in the business of effecting transactions in securities for the account of others' (Section 3(a)(4)(A)), and a 'dealer' is 'any person engaged in the business of buying and selling securities … for such person’s own account through a broker or otherwise' (Section 3(a)(5)(A)). An IPO underwriter does both: it buys from the issuer and it sells onward. Section 15(b)(8) is the provision that puts the underwriting firms inside a self-regulatory organization's jurisdiction — the reason a FINRA rulebook applies to the underwriting terms of an offering registered under a different statute. Section 15(b)(9) permits the Commission, by rule or order, to exempt a broker or dealer from paragraph (8) as it deems consistent with the public interest and the protection of investors.

Source: Securities Exchange Act of 1934, Sections 3(a)(4)(A), 3(a)(5)(A), 15(a)(1) and 15(b)(8)-(9) — U.S. GPO compilation (govinfo) ↗

What is the independent registered public accounting firm's position in the filing?

It is the party that audits and reports on the financial statements in the registration statement, and it holds that position by federal licence. Section 102(a) of the Sarbanes-Oxley Act of 2002 provides that 'it shall be unlawful for any person that is not a registered public accounting firm to prepare or issue, or to participate in the preparation or issuance of, any audit report with respect to any issuer.' Registration is with the Public Company Accounting Oversight Board, established by Section 101(a) 'to oversee the audit of public companies that are subject to the securities laws' — a body corporate that operates as a nonprofit corporation and that, under Section 101(b), 'shall not be an agency or establishment of the United States Government.'

The Securities Act then fixes the firm's position inside the document. Section 7(a) provides that if any accountant 'is named as having prepared or certified any part of the registration statement, or is named as having prepared or certified a report or valuation for use in connection with the registration statement, the written consent of such person shall be filed with the registration statement.' Section 11(a)(4) makes every accountant 'who has with his consent been named as having prepared or certified any part of the registration statement' suable — but only 'with respect to the statement in such registration statement, report, or valuation, which purports to have been prepared or certified by him.' The auditor's exposure is therefore bounded by what it certified, unlike the issuer's. Independence, PCAOB standards, the audit report and critical audit matters are covered in depth on the IPO Accountant page of the IPO Center; the expertised/non-expertised line is covered on the IPO Due Diligence page.

Source: Sarbanes-Oxley Act of 2002, Sections 101(a)-(b) and 102(a) — U.S. GPO (govinfo); Securities Act of 1933, Sections 7(a) and 11(a)(4) ↗

What is issuer's counsel's named contribution to the registration statement?

The legality opinion. Regulation S-K Item 601(b)(5)(i) requires, as an exhibit to the registration statement, 'an opinion of counsel as to the legality of the securities being registered, indicating whether they will, when sold, be legally issued, fully paid and non-assessable, and, if debt securities, whether they will be binding obligations of the registrant.' In the Item 601(a) exhibit table, exhibit 5 ('Opinion re legality') is marked as required for Securities Act registration forms, including Form S-1 — which is why it appears in an IPO exhibit index, conventionally as Exhibit 5.1.

Item 601(b)(23) requires a separate exhibit, 'Consents of experts and counsel.' For Securities Act filings, Item 601(b)(23)(i) provides that 'All written consents required to be filed shall be dated and manually signed,' and that where the consent of an expert or counsel is contained in the report or opinion or elsewhere in the registration statement, 'a reference shall be made in the index to the report, the part of the registration statement or document or opinion, containing the consent.' Securities Act Rule 436(a) adds that if any portion of the report or opinion of an expert or counsel 'is quoted or summarized as such in the registration statement or in a prospectus, the written consent of the expert or counsel shall be filed as an exhibit … and shall expressly state that the expert or counsel consents to such quotation or summarization.' A tax-matters opinion (exhibit 8) is required under Item 601(b)(8) for filings on Form S-11 or those to which Securities Act Industry Guide 5 applies, and otherwise 'need only be filed with the other applicable registration forms where the tax consequences are material to an investor and a representation as to tax consequences is set forth in the filing.'

Source: Reg S-K Item 601(b)(5), (b)(8) and (b)(23) (17 CFR 229.601) ↗

Where do the SEC's rules address counsel acting for the underwriters?

In Securities Act Rule 436(e), which addresses the point directly and narrowly: 'Where a counsel is named as having acted for the underwriters or selling security holders, no consent will be required by reason of his being named as having acted in such capacity.' Counsel retained by the underwriting syndicate is therefore not drawn into the consent regime merely by being identified in that capacity — a different position from issuer's counsel, whose legality opinion is a required exhibit under Item 601(b)(5) and whose consent is filed under Item 601(b)(23).

Rule 436 draws the line at expertising rather than at retention. Rule 436(b) provides that where it is stated that information in the registration statement 'has been reviewed or passed upon by any persons and that such information is set forth in the registration statement upon the authority of or in reliance upon such persons as experts, the written consents of such persons shall be filed as exhibits.' Rule 436(f) adds that 'where the opinion of one counsel relies upon the opinion of another counsel, the consent of the counsel whose prepared opinion is relied upon need not be furnished.' The underwriters' own liability position under Section 11(a)(5) and the reasonable-investigation defense under Section 11(b)(3) are covered on the IPO Due Diligence page of the IPO Center. As published on eCFR, Rule 436 carries a note that an amendment published at 89 FR 21919 (March 28, 2024) was delayed indefinitely at 89 FR 25804 (April 12, 2024); the text described here is the rule as currently in force.

Source: Securities Act Rule 436(b), (e) and (f) (17 CFR 230.436) ↗

What is the SEC's position in an IPO — and what does effectiveness not signify?

Section 4(a) of the Securities Exchange Act establishes 'a Securities and Exchange Commission … to be composed of five commissioners to be appointed by the President by and with the advice and consent of the Senate.' Not more than three commissioners may be members of the same political party; appointments alternate between parties as nearly as practicable; each commissioner holds office for a term of five years and until a successor is appointed and qualified; and no commissioner may engage in any other business, vocation or employment, or participate in stock-market operations or transactions of a character subject to regulation by the Commission.

IPO registration statements are reviewed by the staff of the Commission's Division of Corporation Finance, which the SEC describes as seeking to ensure that investors are provided with the information needed to make informed investment and voting decisions, including when a company initially offers its securities to the public and on an ongoing basis. What that review does not amount to is fixed by statute: under Securities Act Section 23, neither the fact that a registration statement has been filed or is in effect, nor the fact that a stop order is not in effect, 'shall be deemed a finding by the Commission that registration statement is true and accurate on its face … or be held to mean that the Commission has in any way passed upon the merits of, or given approval to, such security,' and 'it shall be unlawful to make, or cause to be made, to any prospective purchaser any representation contrary to the foregoing provisions of this section.' Regulation S-K Item 501(b)(7) carries that into the prospectus itself as the Commission legend. The staff's review mechanics are covered on the SEC Comment Letters page of the IPO Center.

Source: Securities Exchange Act of 1934, Section 4(a) — U.S. GPO compilation (govinfo); Securities Act of 1933, Section 23; SEC, Division of Corporation Finance ↗

What is the exchange's role, and what legal status does it hold?

The exchange is the market the shares list on, and it is itself a registered, rule-enforcing institution. Section 3(a)(1) of the Exchange Act defines an 'exchange' as any organization, association, or group of persons 'which constitutes, maintains, or provides a market place or facilities for bringing together purchasers and sellers of securities or for otherwise performing with respect to securities the functions commonly performed by a stock exchange as that term is generally understood.' Section 6(a) provides that an exchange may be registered as a national securities exchange by filing with the Commission an application containing the rules of the exchange and such other information as the Commission prescribes.

Section 6(b)(1) bars registration unless the Commission determines that the exchange 'is so organized and has the capacity to be able to carry out the purposes of this title and to comply, and … to enforce compliance by its members and persons associated with its members' with the Act, the rules thereunder, and the rules of the exchange. Section 3(a)(26) makes a national securities exchange a 'self-regulatory organization,' and Section 19(g)(1) requires every self-regulatory organization to comply with the Act, the rules thereunder and its own rules, and, 'absent reasonable justification or excuse,' to enforce compliance by its members and persons associated with its members. An exchange's listing standards are its own rules, applied to the company's listing application — a step covered on the Exchange Listing Application page of the IPO Center, with the wider listing landscape on the Wall Street and Listings page. Admission to a market is not a judgment on the offering: under Securities Act Section 23, no such judgment is implied by any part of the registration process.

Source: Securities Exchange Act of 1934, Sections 3(a)(1), 3(a)(26), 6(a), 6(b)(1) and 19(g)(1) — U.S. GPO compilation (govinfo) ↗

What is FINRA's legal position relative to the underwriters?

FINRA is the registered national securities association to which the IPO underwriters belong, and therefore a self-regulatory organization under Section 3(a)(26) of the Exchange Act. Section 15A(a) provides that an association of brokers and dealers may be registered as a national securities association by filing with the Commission an application containing the rules of the association and such other information as the Commission prescribes. Section 15A(b) bars registration unless the Commission makes the enumerated determinations, including that the association 'is so organized and has the capacity to be able to carry out the purposes of this title and to comply, and … to enforce compliance by its members and persons associated with its members' with the Act, the rules thereunder, and the association's own rules.

The connection to an IPO runs through Section 15(b)(8): because the underwriters are registered broker-dealers that do not effect transactions solely on an exchange of which they are members, they must be members of a registered securities association — FINRA. Section 19(g)(1)(B) then obliges FINRA, absent reasonable justification or excuse, to enforce its members' and associated persons' compliance with the Act, the rules thereunder, its own rules and the rules of the Municipal Securities Rulemaking Board. Its Rule 5110 — the Corporate Financing Rule, on underwriting terms and arrangements, which FINRA's rulebook records as amended by SR-FINRA-2025-003 effective March 30, 2026 — governs the filing and review of underwriting terms and compensation in public offerings; that review, and FINRA's own institutional character as a private self-regulatory body, are covered on the FINRA Corporate Financing Review page of the IPO Center.

Source: Securities Exchange Act of 1934, Sections 15A(a)-(b), 3(a)(26), 15(b)(8) and 19(g)(1)(B) — U.S. GPO compilation (govinfo); FINRA Rule 5110 (rulebook — described, not reproduced) ↗

What does the transfer agent do, and what makes a party a 'registrar'?

Section 3(a)(25) of the Exchange Act defines 'transfer agent' as any person who engages, on behalf of an issuer of securities or on behalf of itself as an issuer, in '(A) countersigning such securities upon issuance; (B) monitoring the issuance of such securities with a view to preventing unauthorized issuance, a function commonly performed by a person called a registrar; (C) registering the transfer of such securities; (D) exchanging or converting such securities; or (E) transferring record ownership of securities by bookkeeping entry without physical issuance of securities certificates.' The registrar is therefore not a separate statutory party — it is clause (B) of the transfer-agent definition.

Section 17A(c)(1) makes it unlawful for any transfer agent, unless registered in accordance with that section, to use the mails or any means or instrumentality of interstate commerce to perform the function of a transfer agent with respect to any security registered under Section 12 of the Act. Where the Commission is the appropriate regulatory agency, Exchange Act Rule 17Ac2-1(a) requires the application to be filed on Form TA-1, and it 'shall become effective on the thirtieth day following the date on which the application is filed, unless the Commission takes affirmative action to accelerate, deny or postpone such registration'; Rule 17Ac2-1(c) requires an amendment within sixty days if reported information becomes inaccurate, misleading or incomplete, and Rule 17Ac2-1(d) requires electronic filing on EDGAR. The SEC states that transfer agents 'record changes of ownership, maintain the issuer’s security holder records, cancel and issue certificates, and distribute dividends,' that Section 17A(c) requires transfer agents to be registered with the SEC or, if the transfer agent is a bank, with a bank regulatory agency, and that 'There is no SRO that governs transfer agents.'

Source: Securities Exchange Act of 1934, Sections 3(a)(25) and 17A(c)(1) — U.S. GPO compilation (govinfo); Exchange Act Rule 17Ac2-1; SEC, Transfer Agents ↗

Who actually transmits the IPO filings to the SEC — what is a 'filing agent'?

Regulation S-T defines the role. Under Rule 11, 'the term filing agent means any person or entity engaged in the business of making submissions on EDGAR on behalf of electronic filers. To act as a delegated entity for an electronic filer, a filing agent must be an electronic filer with an EDGAR account.' Financial printers and comparable service providers act in this capacity. The reason the role exists is Rule 101(a)(1)(i), which mandates electronic format for 'Registration statements and prospectuses filed pursuant to the Securities Act … or registration statements filed pursuant to Section 12(b) or 12(g) of the Exchange Act,' together with any related correspondence and supplemental information.

The regulated status stays with the filer, not the agent. Rule 11 defines an 'electronic filer' as a person or entity that submits filings electronically pursuant to Rules 100 and 101, and a 'delegated entity' as 'an electronic filer that another electronic filer authorizes, on the dashboard, to file on EDGAR on its behalf' — delegated entities must themselves be electronic filers, must follow all rules applicable to electronic filers, and 'are not permitted to further delegate authority to file for a delegating electronic filer.' Before filing on EDGAR, Rule 10(b) requires each electronic filer to file the information required by Form ID, the application for EDGAR access, and to upload as a PDF attachment a notarized document, signed by the filer or its authorized individual, confirming the authenticity of the Form ID filing. Rule 301 incorporates the EDGAR Filer Manual by reference — Volume I, 'General Information,' Version 43 (effective March 16, 2026), and Volume II, 'EDGAR Filing,' Version 77 (March 16, 2026). Locating the resulting filings on EDGAR is covered on the Transaction Navigator page of the IPO Center.

Source: Reg S-T Rule 11 (17 CFR 232.11); Rule 101(a)(1)(i) (17 CFR 232.101); Rule 10(b) (17 CFR 232.10); Rule 301 (17 CFR 232.301) ↗

What is the investor's position in the offering, in law?

The investors are the purchasers at the end of the distribution, and the Securities Act gives them two distinct positions. Under Section 11(a), where any part of the registration statement, when that part became effective, contained an untrue statement of a material fact or omitted a material fact required or necessary to make the statements not misleading, 'any person acquiring such security (unless it is proved that at the time of such acquisition he knew of such untruth or omission) may, either at law or in equity, in any court of competent jurisdiction, sue' the five categories of defendant the section lists. No relationship with the defendant is required.

Section 12(a)(2) is the narrower, privity-based position: a person who offers or sells a security by means of a prospectus or oral communication containing an untrue statement of a material fact or a misleading omission (the purchaser not knowing of it), and who cannot sustain the burden of proving 'that he did not know, and in the exercise of reasonable care could not have known, of such untruth or omission,' is liable 'to the person purchasing such security from him' — for the consideration paid with interest, less income received, on tender of the security, or for damages if the purchaser no longer owns it. Section 11(a) itself adds one timing condition: where the person acquired the security after the issuer has made generally available to security holders an earning statement covering at least twelve months beginning after the effective date, recovery is conditioned on proof of reliance, 'but such reliance may be established without proof of the reading of the registration statement by such person.' Which investors can buy, and how each prospectus reaches them, is covered on the Investors and IPO Demand page of the IPO Center.

Source: Securities Act of 1933, Sections 11(a) and 12(a)(2) — U.S. GPO compilation (govinfo) ↗

Who's who in an IPO: each party, its function, and the authority that defines or regulates it

Each row names one participant, states its function in the offering, and identifies the provision that defines or regulates it. The federal statutes and the Code of Federal Regulations are U.S. Government works in the public domain (17 U.S.C. 105) and are quoted here; FINRA's rulebook is described and linked, not reproduced. The linked source for each row is the primary authority for the entry in the 'Defining or regulating authority' column.

Party Function in the IPO Defining or regulating authority Source
Issuer The company whose securities are registered; 'every person who issues or proposes to issue any security'; files and signs the registration statement, and alone cannot assert the Section 11(b) defenses Securities Act §2(a)(4); §6(a); §11(b) Securities Act §2(a)(4) · source
Signing officers and directors The principal executive officer(s), principal financial officer, comptroller or principal accounting officer, and a majority of the board must sign at least one copy of the registration statement Securities Act §6(a); liability under §11(a)(1)-(3) Securities Act §6(a) · source
Underwriter Purchases from the issuer with a view to distribution, or offers or sells for the issuer in connection with the distribution, or participates in the undertaking Securities Act §2(a)(11); liability under §11(a)(5) Securities Act §2(a)(11) · source
Underwriter (as a firm) Must be an SEC-registered broker-dealer and, unless it trades solely on an exchange of which it is a member, a member of a registered securities association Exchange Act §3(a)(4)(A), §3(a)(5)(A), §15(a)(1), §15(b)(8) Exchange Act §15(b)(8) · source
Independent registered public accounting firm Audits and certifies financial statements in the registration statement; its written consent is filed with the filing; liable only for the portion purporting to be prepared or certified by it Sarbanes-Oxley §102(a); Securities Act §7(a), §11(a)(4) Sarbanes-Oxley Act §102(a) · source
PCAOB Registers and oversees the firms that audit issuers; a nonprofit body corporate that 'shall not be an agency or establishment of the United States Government' Sarbanes-Oxley §101(a), §101(b), §102(a) Sarbanes-Oxley Act §101 · source
Issuer's counsel Gives the exhibit 5 opinion on the legality of the securities being registered; its consent is filed in the exhibit 23 consents of experts and counsel Reg S-K Item 601(b)(5)(i); Item 601(b)(23); Rule 436(a) 17 CFR 229.601 · source
Underwriters' counsel Acts for the underwriters; being named as having acted in that capacity triggers no consent requirement by reason of the naming alone Securities Act Rule 436(e); see also Rule 436(f) 17 CFR 230.436 · source
U.S. Securities and Exchange Commission Five-commissioner federal agency; its Division of Corporation Finance staff reviews the registration statement; effectiveness is no finding on the merits of, or approval of, the security Exchange Act §4(a); Securities Act §23; Reg S-K Item 501(b)(7) SEC, Division of Corporation Finance · source
National securities exchange The venue where the class lists and trades; a self-regulatory organization that must have the capacity to enforce member compliance with the Act and with its own rules Exchange Act §3(a)(1), §6(a), §6(b)(1), §3(a)(26), §19(g)(1) Exchange Act §6(b)(1) · source
FINRA The registered national securities association the underwriters must belong to; its Corporate Financing Rule governs the filing and review of underwriting terms and compensation Exchange Act §15A(a)-(b), §3(a)(26), §19(g)(1)(B); FINRA Rule 5110 FINRA Rule 5110 (rulebook) · source
Transfer agent / registrar Countersigns securities on issuance, registers transfers, and transfers record ownership by bookkeeping entry; the registrar function is monitoring issuance to prevent unauthorized issuance Exchange Act §3(a)(25); §17A(c)(1); Rule 17Ac2-1 (Form TA-1) SEC, Transfer Agents · source
Financial printer / EDGAR filing agent Makes submissions on EDGAR on behalf of the electronic filer; the filer, not the agent, holds the EDGAR account and the filing obligation Reg S-T Rule 11 (filing agent; delegated entity); Rule 101(a)(1)(i); Rule 10(b) 17 CFR 232.11 · source
Investors The purchasers in the distribution; may sue as 'any person acquiring such security' under Section 11(a), and as 'the person purchasing such security from' the seller under Section 12(a)(2) Securities Act §11(a); §12(a)(2) Securities Act §11(a) · source

Key terms, defined

Issuer (Securities Act §2(a)(4))
'Every person who issues or proposes to issue any security.' The definition carries exceptions for certificates of deposit, voting-trust and collateral-trust certificates, certain unincorporated investment trusts, equipment-trust certificates (where the issuer is 'the person by whom the equipment or property is or is to be used'), and fractional undivided interests in oil, gas or other mineral rights. In an IPO the issuer is the company registering its shares; under Section 6(a) it is also a signatory of the registration statement.
Underwriter (Securities Act §2(a)(11))
'Any person who has purchased from an issuer with a view to, or offers or sells for an issuer in connection with, the distribution of any security, or participates or has a direct or indirect participation in any such undertaking, or participates or has a participation in the direct or indirect underwriting of any such undertaking.' The term excludes a person 'whose interest is limited to a commission from an underwriter or dealer not in excess of the usual and customary distributors’ or sellers’ commission.' For this paragraph, 'issuer' includes any person controlling, controlled by, or under common control with the issuer.
Broker and dealer (Exchange Act §3(a)(4)(A), §3(a)(5)(A))
A 'broker' is 'any person engaged in the business of effecting transactions in securities for the account of others.' A 'dealer' is 'any person engaged in the business of buying and selling securities … for such person’s own account through a broker or otherwise.' Each definition carries statutory exceptions, including for specified bank activities. An IPO underwriting firm ordinarily falls within both, and Section 15(a)(1) makes it unlawful for such a firm to use the mails or interstate commerce to effect securities transactions unless registered with the Commission.
Registered national securities association (Exchange Act §15A)
An association of brokers and dealers registered with the SEC under Section 15A(b) after the Commission determines, among other things, that it is organized and has the capacity to comply with, and to enforce its members' compliance with, the Exchange Act, the rules thereunder and the association's own rules. Under Section 3(a)(26) a registered securities association is a 'self-regulatory organization,' and Section 15(b)(8) requires a registered broker-dealer to be a member of one unless it effects transactions solely on a national securities exchange of which it is a member. FINRA is the registered national securities association to which IPO underwriters belong.
Transfer agent (Exchange Act §3(a)(25))
Any person who engages, on behalf of an issuer of securities or on behalf of itself as an issuer, in countersigning securities upon issuance; monitoring issuance to prevent unauthorized issuance; registering transfers; exchanging or converting securities; or transferring record ownership by bookkeeping entry without physical issuance of certificates. The term excludes an insurance company or separate account performing those functions solely for variable annuity contracts or variable life policies it issues, and a registered clearing agency performing them solely for options contracts it issues. Section 17A(c)(1) requires registration.
Registrar (Exchange Act §3(a)(25)(B))
Not a separate statutory party but a named function inside the transfer-agent definition: clause (B) covers 'monitoring the issuance of such securities with a view to preventing unauthorized issuance, a function commonly performed by a person called a registrar.' A person performing that function on behalf of an issuer is a transfer agent for purposes of the Exchange Act and is subject to the Section 17A(c)(1) registration requirement on that basis.
Opinion re legality (exhibit 5)
The exhibit required by Regulation S-K Item 601(b)(5)(i): 'An opinion of counsel as to the legality of the securities being registered, indicating whether they will, when sold, be legally issued, fully paid and non-assessable, and, if debt securities, whether they will be binding obligations of the registrant.' The Item 601(a) exhibit table marks exhibit 5 as required for the Securities Act registration forms used in an IPO. Item 601(b)(5)(ii)-(iii) adds requirements where the securities are issued under a plan subject to ERISA.
Consents of experts and counsel (exhibit 23)
The exhibit required by Regulation S-K Item 601(b)(23). For Securities Act filings, Item 601(b)(23)(i) provides that 'All written consents required to be filed shall be dated and manually signed,' and that where the consent is contained in the expert's or counsel's report or opinion, or elsewhere in the registration statement or a document filed with it, the index must reference the location of the consent. The underlying obligation is Securities Act Section 7(a), and Securities Act Rule 436 sets out when a consent is and is not required.
Filing agent (Reg S-T Rule 11)
'Any person or entity engaged in the business of making submissions on EDGAR on behalf of electronic filers. To act as a delegated entity for an electronic filer, a filing agent must be an electronic filer with an EDGAR account.' Rule 11 separately defines a 'delegated entity' as an electronic filer that another electronic filer authorizes, on the dashboard, to file on EDGAR on its behalf, and provides that delegated entities must themselves follow all rules applicable to electronic filers and may not further delegate that authority.
Commission legend (Reg S-K Item 501(b)(7))
The prospectus legend required by Item 501(b)(7): 'A legend that indicates that neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities or passed upon the accuracy or adequacy of the disclosures in the prospectus and that any contrary representation is a criminal offense.' The Item supplies two example formulations and permits other clear, plain language. Its statutory counterpart is Securities Act Section 23, which makes a representation contrary to that principle unlawful.

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1BusinessWorld IPO Center, "The IPO Ecosystem." Compiled from U.S. Government primary sources — the Securities Act of 1933 (Sections 2(a)(4), 2(a)(11), 6(a), 7(a), 11, 12(a)(2) and 23), the Securities Exchange Act of 1934 (Sections 3(a)(1), 3(a)(4), 3(a)(5), 3(a)(25), 3(a)(26), 4(a), 6, 15, 15A, 17A(c) and 19(g)), the Sarbanes-Oxley Act of 2002 (Sections 101 and 102), SEC Regulation S-K (Items 501 and 601), Securities Act Rule 436, Regulation S-T (Rules 10, 11, 101 and 301), Exchange Act Rule 17Ac2-1, and the SEC's official role pages — the primary authority for each section linked inline. Retrieved 2026-07-17.

The IPO Center is informational only. It is provided by 1BusinessWorld strictly for general informational and educational purposes. Nothing in the IPO Center constitutes, or should be construed as, legal, accounting, auditing, underwriting, tax, investment, financial, valuation, listing, or other professional advice, or a recommendation, endorsement, solicitation, or offer to buy or sell any security or to engage in any transaction. 1BusinessWorld is not a law firm, accounting firm, auditor, broker-dealer, underwriter, investment adviser, or securities exchange, and nothing in the IPO Center creates any advisory, fiduciary, attorney-client, or other professional relationship with 1BusinessWorld. Although the IPO Center references official materials published by regulators, exchanges, and other authorities, 1BusinessWorld makes no representation or warranty, express or implied, as to the accuracy, completeness, timeliness, or fitness for any purpose of any content, and, to the fullest extent permitted by law, disclaims all liability for any loss or damage of any kind arising directly or indirectly from the use of, or reliance on, any information presented. Securities laws, regulations, listing standards, and market practices change frequently and differ by jurisdiction; readers must verify all information against the current official text and consult qualified legal, accounting, underwriting, tax, investor-relations, and other professional advisors before acting. Any decision relating to an initial public offering or any securities transaction is made solely at the reader's own risk. Last reviewed: July 17, 2026.