Bookbuilding, Pricing, Allocation, and Stabilization

Underwriters build an order book of investor indications, recommend a price, and allocate shares under FINRA Rules 5130 and 5131, which bar sales to restricted persons and prohibit quid pro quo and spinning allocations ^[1][2][3]. FINRA Rule 5110 polices the fairness of underwriting compensation and caps the overallotment option at 15% of the offering ^[4]. After pricing, the syndicate may stabilize under Regulation M Rule 104 at no more than the offering price, and lock-ups, typically 180 days, govern when insiders can sell ^[1][6].

The syndicate and the order book

Underwriters are the investment banks that manage and sell the IPO for the company ^[1]. The prospectus must name the principal underwriters, state the amounts each underwrites, and describe the nature of their obligation, in particular whether they are committed to take and pay for all the securities if any are taken (a firm commitment) or only those they can sell (best efforts) ^[5]. The underwriters collect indications of interest, and their compilation of those indications, showing how many shares each investor would buy and at what price, is the order book ^[1].

FINRA Rule 5131 gives the issuer visibility into that book. In a new issue, the book-running lead manager must give the issuer's pricing committee, or its board if there is no committee, regular reports of indications of interest, including the names of interested institutional investors and the shares each indicated, plus aggregate retail demand ^[2]. After settlement, the lead manager must report the final allocations to institutional investors by name and the aggregate sales to retail investors ^[2].

Setting the price

The SEC describes the offering price as a negotiated estimate reached by the company and underwriters through a mix of market conditions, analysis, and negotiation ^[1]. The incentives compete: a higher price raises more capital for the company, and underwriter compensation is typically a percentage of the offering price, but underwriters also want a price attractive to the investors they sell to, and underpricing can produce a first-day jump that benefits those investors more than the company ^[1]. Valuation analyses based on revenues, customers, and financial results, together with the order book, inform the final number ^[1].

Underwriting compensation and FINRA Rule 5110

The difference between the public offering price and the price the underwriters pay the issuer is the gross spread, or underwriting discount. Item 508(e) of Regulation S-K requires a table showing the discounts and commissions paid to the underwriters per share and in total, separately for the company and any selling shareholders, along with all other items FINRA considers underwriting compensation ^[5]. FINRA Rule 5110 defines underwriting compensation broadly as any payment, right, interest, or benefit a participating member receives from any source for underwriting, allocation, distribution, advisory, and other investment banking services in a public offering ^[4].

Rule 5110 prohibits members from participating in a public offering whose terms, including the aggregate underwriting compensation, are unfair or unreasonable ^[4]. For offerings that must be filed, no member may distribute or sell the securities until the required documents have been filed with FINRA and FINRA has issued an opinion that it has no objection to the proposed terms ^[4]. Among the arrangements the rule treats as unreasonable is any overallotment option in a firm-commitment offering that covers more than 15% of the securities offered, excluding the option shares themselves ^[4].

Who may receive IPO shares: FINRA Rules 5130 and 5131

Rule 5130 prohibits a FINRA member from selling a new issue to any account in which a restricted person has a beneficial interest, unless an exemption applies ^[3]. A new issue means an IPO of an equity security made under a registration statement or offering circular ^[3]. Restricted persons include broker-dealers and their personnel, finders and fiduciaries of the managing underwriter such as attorneys and accountants, and portfolio managers who buy or sell securities for institutions, along with certain of their immediate family members ^[3].

General exemptions cover, among others, registered investment companies and any account in which restricted persons hold no more than 10% of the beneficial interests in aggregate ^[3]. Before selling a new issue to an account, the member must have obtained in good faith, within the prior twelve months, a representation about the account's eligibility ^[3].

• Quid pro quo: no member may offer or threaten to withhold new-issue shares as an inducement for compensation that is excessive in relation to the services provided ^[2].
• Spinning: no member may allocate new-issue shares to an account of an executive officer or director of a public company or covered non-public company if the company is a current investment banking client, has paid the member for investment banking services in the past 12 months, or is expected to retain the member within the next 3 months, or on the condition of future business ^[2].
• Flipping: a member may not claw back a salesperson's credit because a customer flipped shares unless the managing underwriter has assessed a penalty bid on the entire syndicate ^[2].
• Returned shares: shares returned to the syndicate while trading at a premium must be used to cover the syndicate short or, if none exists, offered to unfilled customer orders by random allocation or sold with the profits donated to charity ^[2].

The SEC's investor bulletin adds that underwriters may discourage flipping by declining to allocate IPO shares to customers who have flipped before, but that flipping alone is not prohibited by the federal securities laws ^[1].

Overallotment, the greenshoe, and stabilization

Regulation M defines a syndicate covering transaction as a bid or purchase on behalf of the syndicate to reduce a short position created in connection with the offering, and a penalty bid as an arrangement that lets the managing underwriter reclaim a selling concession from a syndicate member when shares it sold are repurchased in covering transactions ^[7]. Stabilizing means placing a bid or making a purchase to peg, fix, or maintain the price of a security ^[7].

Rule 104 permits stabilizing only to prevent or retard a decline in the market price, and no stabilizing bid may exceed the lower of the offering price or the stabilizing bid in the principal market ^[6]. Stabilizing is prohibited in at-the-market offerings, and anyone effecting a syndicate covering transaction or imposing a penalty bid must give prior notice to the self-regulatory organization overseeing the principal market ^[6]. The prospectus must describe any stabilizing, syndicate covering, or penalty-bid transactions the underwriters intend to conduct and, if true, that they may stop at any time ^[5]. The SEC's investor bulletin warns that once underwriter support ends, the stock price may decline significantly ^[1].

Lock-ups and overhang

Existing shareholders often agree not to sell for a set period after the IPO, typically 180 days ^[1]. Separately, shares bought in private placements are generally restricted securities, and Rule 144 requires a holding period of at least six months after acquisition if the issuer has been a reporting company for at least 90 days, or one year otherwise, before they can be resold under that rule ^[8]. FINRA Rule 5131 requires that lock-ups of officers and directors also cover their issuer-directed shares, and that the lead manager announce any release or waiver of such a lock-up through a major news service at least two business days before it takes effect, with limited exceptions ^[2]. Shares that are outstanding but cannot yet trade are sometimes called the market overhang, and when lock-ups expire the price may fall significantly if many shares become available at once ^[1].

Key terms

Order book

The underwriters' compilation of investor indications of interest, including share amounts and prices.

Gross spread

The underwriting discount: the difference between the public offering price and the price the underwriters pay the issuer.

Firm commitment

An underwriting in which the underwriters commit to take and pay for all the securities if any are taken.

Restricted person

Under FINRA Rule 5130, a person such as broker-dealer personnel, certain finders and fiduciaries, or portfolio managers, who generally may not buy new issues.

Spinning

Allocating IPO shares to executives or directors of investment banking clients to win or reward business; prohibited by FINRA Rule 5131.

Overallotment (greenshoe) option

An option letting the underwriters buy additional shares from the issuer, capped by FINRA Rule 5110 at 15% of the offering.

Syndicate covering transaction

Under Regulation M, a bid or purchase by the syndicate to reduce a short position created in the offering.

Penalty bid

An arrangement allowing the managing underwriter to reclaim a selling concession when shares a syndicate member sold are bought back in covering transactions.

Lock-up agreement

A contractual promise by existing shareholders not to sell for a period after the IPO, typically 180 days.

Check your understanding

Sources

1. [1]U.S. Securities and Exchange Commission, Office of Investor Education and Advocacy, “Investor Bulletin: Investing in an IPO (SEC Pub. No. 133),” February 2013.
2. [2]Financial Industry Regulatory Authority, “FINRA Rule 5131 — New Issue Allocations and Distributions,” Accessed November 2026.
3. [3]Financial Industry Regulatory Authority, “FINRA Rule 5130 — Restrictions on the Purchase and Sale of Initial Equity Public Offerings,” Accessed November 2026.
4. [4]Financial Industry Regulatory Authority, “FINRA Rule 5110 — Corporate Financing Rule: Underwriting Terms and Arrangements,” Accessed November 2026.
5. [5]Electronic Code of Federal Regulations (eCFR), “17 CFR 229.508 (Item 508 of Regulation S-K) — Plan of distribution,” Accessed November 2026.
6. [6]Electronic Code of Federal Regulations (eCFR), “17 CFR 242.104 — Stabilizing and other activities in connection with an offering,” Accessed November 2026.
7. [7]Electronic Code of Federal Regulations (eCFR), “17 CFR 242.100 — Definitions (Regulation M),” Accessed November 2026.
8. [8]Electronic Code of Federal Regulations (eCFR), “17 CFR 230.144 — Persons deemed not to be engaged in a distribution and therefore not underwriters,” Accessed November 2026.

Educational content only — not legal, tax, or investment advice, or an offer to sell or a solicitation of an offer to buy any security. Rules and data are described as of November 2026 and may change. Securities offered through Umergence LLC, Member FINRA/SIPC.