The IPO Process Overview: Timeline, Phases, and Key Players

Introduction

No other transaction an ECM banker works on takes 12 to 18 months, runs through a working group of fifteen to thirty professionals, and ends with a single overnight pricing decision that fixes the price of every share. The IPO does. The shape is consistent enough that any banker can sketch it on a whiteboard: a long preparation phase, a compressed marketing window, and one execution night. The variation lives in the issuer's complexity, the SEC's review intensity, and whether the market window stays open long enough to land the deal.

Every IPO splits into three recognizable phases: pre-launch, marketing, and execution. The boundaries between them are not perfectly clean, but the work in each phase is distinct enough that bankers organize their calendars and their staffing around the shape.

Pre-Launch: Preparation, S-1 Drafting, and SEC Review

Pre-launch runs from underwriter mandate to SEC effectiveness, and almost everything that determines whether the deal succeeds happens inside it. The working group runs diligence, drafts the S-1, files it (publicly or confidentially under the JOBS Act EGC pathway), iterates through SEC comment letters, and shapes the equity story and analyst materials in parallel. The mechanical components are predictable: 30 to 60 days of drafting, then 75 to 120 days of SEC review. The unpredictable component is everything else, which is why six to nine months is the realistic blended duration.

Marketing: Test-the-Waters, Analyst Presentation, and Roadshow

Once the registration is on its way to becoming effective, the marketing phase begins. The bookrunners' research analysts attend a teach-in to receive a comprehensive briefing on the issuer. Test-the-waters meetings under Section 5(d) of the Securities Act let management talk to qualified institutional investors before launch under written confidentiality. The price range gets set, the prospectus is finalized, and management goes on the road for a one- to two-week roadshow visiting the largest institutional accounts in person or by video. Sales coverage on the equity floor talks to investors throughout; syndicate aggregates the orders coming back into the order book.

Execution: Pricing, Allocation, First Trade, and Stabilization

The night before listing, the bookrunner presents the order book to the issuer's pricing committee, recommends a final offer price, and the board approves. Allocation is decided in parallel, with long-only investors typically receiving the largest stakes. The next morning, the stock opens on its listing exchange. The syndicate desk works the greenshoe option to stabilize the stock through the first thirty days. After 180 days the lockup expires and pre-IPO shareholders are free to sell.

An IPO is a working group exercise. The names appearing on the cover of the S-1 capture only a fraction of the people actually doing the work, and understanding who does what is the difference between sounding informed and sounding generic in interviews.

The Issuer Side

The issuer's CEO and CFO are the public faces of the deal: they sign the S-1, sit through diligence, train for the roadshow, and present at every test-the-waters meeting. The general counsel manages the legal workstreams and is the issuer's main point of contact with both sets of counsel. The CFO's finance team builds the financial projections, audit support, and eventual public-company controls. A pre-IPO sponsor (private equity or growth investor) is also a deal participant, with the lead deal partner attending most working group meetings and signing off on major decisions.

The Bank Syndicate

The bank side is led by the bookrunner syndicate. The lead-left bookrunner manages the entire process, coordinates working group calls, drives the equity story, and runs the pricing call. Joint bookrunners share the bookrunner role with smaller portions of the work and the fees. Co-managers play smaller execution roles but contribute distribution and post-IPO research coverage. Within each bank, the coverage and ECM teams work jointly on the deal, with ECM driving the offering mechanics and coverage owning the issuer relationship. A typical large IPO syndicate runs four to six bookrunners and a handful of co-managers, but mega-deals (think Medline's December 2025 listing) can have more than twenty banks across the title page, with the lead-left bookrunner still capturing the largest fee share.

Counsel for Both Sides

Two separate law firms typically work the deal. Issuer's counsel drafts the S-1, manages SEC comments, and advises the company on securities law compliance. Underwriter's counsel reviews the S-1 from the syndicate's perspective, runs separate diligence on the issuer, and produces the underwriting agreement. Both sets of counsel sit through every drafting session, and their input frequently drives changes to the document. The standard US IPO counsel set is well-defined: Latham & Watkins, Davis Polk, Skadden, Cravath, Wachtell, Cooley, Wilson Sonsini, Goodwin Procter, Simpson Thacher, and Kirkland & Ellis dominate the top of the league tables, with each firm serving issuer or underwriter roles depending on the deal. Counsel selection is a meaningful decision because complex S-1s require firms with deep IPO drafting experience.

Auditors and the Comfort Letter

The issuer's audit firm is the third major institutional participant. The auditors sign off on the historical financial statements included in the S-1 (typically two or three years of audited financials plus stub-period interims) and produce a comfort letter to the underwriters at pricing certifying the numbers in the offering. The comfort letter is one of the underwriters' principal protections against Section 11 liability for misstatements in the registration statement. Big Four firms (Deloitte, EY, KPMG, PwC) audit the vast majority of US IPO candidates; smaller national or regional firms occasionally appear on smaller deals but are rare on bulge-bracket-led mandates.

The Financial Printer and the Lesser-Known Players

A few additional participants round out the working group. The financial printer (typically Donnelley, Workiva, or RR Donnelley successors) produces the formatted S-1 and prospectus, manages SEC EDGAR submissions, and runs the printer drafting sessions where the document is finalized in real time. The transfer agent handles the post-IPO share-ownership records. Investor relations advisors are often hired separately to coach management on public-company communications. None of these participants is the headline name on the S-1, but each plays a defined role that, when missed, creates cascading delays.

S-1 Registration Statement

The principal disclosure document for a US IPO. Filed with the SEC under the Securities Act of 1933, the S-1 contains a detailed description of the issuer's business, audited financial statements, risk factors, MD&A, use of proceeds, principal stockholders, plan of distribution, and other prescribed disclosures. The SEC reviews the S-1 through one or more comment letters, and the issuer files amendments (S-1/A) until the statement becomes effective and the offering can launch.

Phase boundaries describe the shape; the step sequence below describes what happens inside them. Deal sizes, sectors, and sponsor structures shift the calendar, but the order of operations holds.

The Jumpstart Our Business Startups Act of 2012 fundamentally restructured the IPO timeline for the majority of issuers. Most US IPO candidates qualify as emerging growth companies (EGCs) and use the JOBS Act accommodations.

Emerging Growth Company (EGC)

A US issuer with less than $1.235 billion in annual gross revenue in its most recent fiscal year (the SEC's inflation-adjusted threshold). EGC status, granted by the JOBS Act of 2012 and refined by subsequent reforms, allows issuers to submit confidential draft registration statements, hold pre-filing test-the-waters meetings with qualified institutions, and use scaled financial and executive-compensation disclosure for up to five years after IPO. The vast majority of US IPO candidates qualify as EGCs.

Confidential Filing for EGCs

EGCs (issuers with less than $1.235 billion of revenue in their most recent fiscal year, the SEC's inflation-adjusted threshold) can submit a draft registration statement (DRS) to the SEC for confidential, non-public review before any public filing. The advantage is significant: the company can iterate through SEC comments without having its draft S-1 visible to competitors, potential acquirers, or the press, and without committing to launch. If the deal does not move forward, the public never sees the draft.

Test-the-Waters and the 15-Day Rule

EGCs (and now most other issuers, after the FAST Act and subsequent reforms) can hold test-the-waters meetings with qualified institutional buyers and accredited institutions before filing or before going effective. The FAST Act of December 2015 reduced the public filing window to 15 days before the roadshow launch, replacing the original 21-day rule under the JOBS Act. The combined effect is a faster, less publicly visible IPO process for the vast majority of US issuers.

Scaled Disclosure

EGCs benefit from reduced financial-statement requirements (two years of audited financials instead of three), reduced executive compensation disclosure, and exemptions from some Sarbanes-Oxley auditor attestation requirements. The scaled disclosure regime extends for up to five years after IPO or until the issuer outgrows the EGC threshold.

The standard timeline is a planning baseline, not a forecast. Most IPOs slip at least once before pricing, and the slippage traces back to one of four sources: the SEC, the market, the issuer, or an external shock that takes the SEC offline.

SEC Comment Cycles

The first round of SEC comments often runs to 30 to 60 line items, ranging from small disclosure tweaks to substantive accounting questions that require auditor sign-off. A second round typically follows, and complex issuers can run through three or four rounds before the SEC clears the deal. Each round adds three to four weeks to the calendar.

Market Windows

SEC clearance does not buy a launch date. The deal still has to land inside an open market window, and the window can shut for reasons unrelated to the issuer: equity-market volatility, a sector-specific selloff, a geopolitical shock, a government shutdown, or a macroeconomic data print. The bank's job is to keep the working group ready to launch when the window opens, not to predict when.

Issuer-Driven Delays

The issuer is the second most common source of slippage and the one bankers have least leverage over. Audit cleanup can run weeks longer than budgeted when restatements or scope expansions surface. Governance changes demanded by the SEC or underwriter counsel land late in drafting. Executive transitions force re-papering. Operational surprises (a customer concentration disclosure needing rework, a regulatory inquiry, a litigation development) each absorb a full comment cycle. Disciplined working groups build buffer because the issuer is the variable they cannot fully control.

Government Shutdowns and Other External Shocks

The Q4 2025 federal government shutdown is the most recent reminder that the SEC review process depends on a functioning federal apparatus. When the SEC pauses processing, deals that were targeting near-term effectiveness slip to the next available window, which has cascading effects across the year-end pipeline. Bankers running deals that touch the end of any calendar quarter watch government funding deadlines closely for exactly this reason.

The US process above is the reference template, not the only one. Bulge bracket ECM teams run cross-border mandates continuously, and a New York-based candidate will work on Hong Kong, London, and EU listings alongside US deals. The mechanics translate; the documents, regulators, and cornerstone-investor practice vary.

Hong Kong (HKEX)

A Hong Kong IPO follows the HKEX Listing Rules and runs on a different document (the prospectus) and a different review body (the Stock Exchange of Hong Kong, with parallel involvement from the Securities and Futures Commission). The timeline can be faster than the US in some cases because cornerstone investors are pre-committed before launch, providing demand certainty that lets the deal price faster after the public phase begins. The "A+H" listing model that drove much of the 2024-2025 HKEX boom adds further speed for mainland-Chinese A-share companies dual-listing on HKEX, because the issuer's financials are already audited and disclosed under PRC regulations.

London (LSE) and the EU

UK IPOs follow the FCA Listing Rules (recently overhauled into a single regime, replacing the prior premium and standard segments) and trade on either the London Stock Exchange's Main Market or AIM. EU IPOs follow each member state's competent-authority rules under the EU Prospectus Regulation, harmonized by the EU Listing Act. Both UK and EU timelines tend to be similar in length to the US for comparable-size deals, with the largest difference being earlier and more formal involvement of cornerstone and anchor investors than is typical in US deals.

What Stays Constant Across Jurisdictions

The structural logic of an IPO is invariant across venues: a multi-month preparation phase, a regulator-driven review, a marketing phase that builds indicative demand, and a pricing decision that allocates a finite supply of shares. What changes between New York, London, and Hong Kong is the document template, the regulator's review style, and the timing of cornerstone commitments. The ECM banker's job does not change with the venue.

Medline Industries' December 2025 IPO illustrates how the timeline above plays out on a real, large, sponsor-backed deal. Blackstone, Carlyle, and Hellman & Friedman acquired Medline in a 2021 buyout valued at roughly $34 billion, one of the largest healthcare LBOs of the prior decade. Within two years, the sponsors had begun preparing the company for a return to public markets.

Pre-Filing: Late 2024 to October 2025

Medline submitted a confidential draft S-1 to the SEC in December 2024. The working group, led by Goldman Sachs, Morgan Stanley, BofA Securities, and JPMorgan, spent roughly ten months iterating through SEC comment cycles confidentially, refining disclosures across MD&A, revenue recognition, segment reporting, and the consolidated capital structure inherited from the LBO. By October 2025, the registration was ready to flip public.

Public Filing and Roadshow: October to December 2025

Medline publicly filed its S-1 on October 28, 2025. The 15-day FAST Act window let the working group launch the roadshow shortly after, with management, the lead bookrunners, and a syndicate that ultimately exceeded forty banks running a multi-week US and international tour. The price range was revised upward as demand built, and the deal ultimately priced at $29 on December 16, 2025.

Pricing and Stabilization: December 2025 Onward

Medline raised the deal size from 179 million shares to 216 million at pricing, generating roughly $6.26 billion in proceeds and making the deal the largest US IPO of 2025. The stock began trading on Nasdaq under MDLN on December 17, the syndicate desk worked the greenshoe through the stabilization window, and the stock finished the year up materially from its IPO price. The visible twelve-month timeline from confidential filing to first trade understates the full arc: the additional two-plus years of pre-filing readiness work by the issuer and sponsors brought the full effort closer to thirty months.

A comment letter is a numbered list of questions and disclosure requests from the staff, and the patterns repeat across IPOs almost predictably. Three areas dominate the typical first round: revenue recognition, non-GAAP and KPIs, and MD&A and risk factors.

Revenue Recognition and Accounting Comments

Revenue recognition under ASC 606 is one of the SEC's most consistent comment areas. The staff frequently asks issuers to explain how they identify performance obligations under multi-element customer contracts, how they allocate transaction price, what significant judgments management has made in estimating variable consideration, and how disaggregation disclosures map to how management actually runs the business. Software, healthcare, and consumer-services issuers see these comments most often because their contract structures are most complex.

Non-GAAP and KPI Comments

The staff comments on non-GAAP financial measures and KPIs in roughly thirty percent of all reviews. The comments push for more prominent presentation of the comparable GAAP measure, clearer reconciliations, and challenges to adjustments that look like they "individually tailor" revenue recognition or other GAAP accounting. Issuers introducing operating KPIs (subscription revenue, net revenue retention, same-store sales metrics, capacity utilization) face SEC pressure to define the metrics clearly, justify the management relevance, and commit to consistent disclosure in subsequent periodic reports.

MD&A and Risk Factor Comments

MD&A receives the most comments of any section. Common themes include thin forward-looking trend disclosure, KPI presentation that needs more context, and inconsistencies between MD&A and the financial statements. Risk factor comments cluster around language too generic to satisfy Item 105's specificity requirement and risks visible in the diligence findings but missing from the risk factors. The working group responds to each comment in writing and incorporates the disclosure changes into the next S-1/A amendment.

Read the timeline as a sequence of decisions, not a calendar. Each phase compresses or expands with how quickly the working group resolves SEC comments, market-window timing, and issuer readiness. The articles below zoom in on each: the bake-off, the working group setup, S-1 drafting, the roadshow, the pricing call, and first-day trading.