When a company goes public, it sells shares to outside investors for the first time through a registered offering, and the cash from that sale lands on its balance sheet. Existing owners keep their shares but own a smaller percentage of a larger pie, and from the first day of trading the company lives under SEC reporting rules, independent board oversight, insider trading restrictions, and continuous public scrutiny of its numbers. The process usually runs six to nine months and permanently changes how the company is financed, governed, and watched.
What Actually Happens on the Way to the Stock Exchange
The company hires one or more investment banks to act as underwriters. The lead underwriter puts together a syndicate of other banks to spread the stock across institutional and retail buyers, because a concentrated shareholder base on day one tends to produce volatile trading.
The formal regulatory step is filing a registration statement on Form S-1 with the Securities and Exchange Commission.1U.S. Securities and Exchange Commission. What Is a Registration Statement? The S-1 describes the business, financial history, management, risk factors, and planned use of proceeds. Until the SEC declares the filing effective, the Securities Act of 1933 limits what the company can say publicly about the offering. This is the “quiet period,” and it exists to keep promotion from distorting investor demand before the facts are on the table.
During the waiting period, senior executives present to large institutional investors in a series of meetings called the roadshow. Underwriters collect non-binding indications of interest, use book building to tally demand at various price points, and set the final share price the evening before trading begins.
The company sells shares to the underwriters at a discount to that public offering price, and the gap is the underwriting fee. For most midsize IPOs raising under roughly $200 million, the fee is a flat 7% of proceeds.2ScienceDirect. The 7% Solution and IPO Underpricing Larger deals negotiate lower rates, with offerings above $1 billion typically paying 4% to 5%. Legal, accounting, and filing costs push total IPO expenses well above 10% of proceeds in many cases.3J.P. Morgan Workplace Solutions. What Happens When a Company Goes Public?
Underwriters usually receive a greenshoe option allowing them to sell up to 15% more shares than planned if demand is strong. The greenshoe doubles as a price stabilization tool: the syndicate oversells the offering to create a short position, and if the stock drops after the first day the banks buy shares in the open market to cover, putting a floor under the price. If the stock rises, they exercise the greenshoe to cover the short with newly issued shares at the offering price.
Once trading opens on an exchange like the NYSE or Nasdaq, the company is public. The opening price is set by supply and demand and may diverge sharply from the offering price. A big first-day jump is often framed as a success, but it also means the company priced its shares too low and left money on the table.
How Much the Original Owners Give Up
Issuing new shares dilutes the existing owners. A company with 80 million shares outstanding that sells 20 million new shares to the public goes from 100% ownership in the original holders’ hands to 80%. The share count held by any individual owner does not change, but each share now represents a smaller slice of the whole.
The counterweight is the cash raised. If the company was worth $4 billion before the IPO and raised $1 billion, the post-money valuation is $5 billion, and in theory the per-share value holds. In practice, the market price after trading begins depends on investor sentiment and often diverges from that arithmetic in both directions.
How Governance Changes Once the Company Is Public
Both the NYSE and Nasdaq require that a majority of board members be independent, meaning they have no material financial or personal ties to the company or its management.4NYSE. NYSE Listed Company Manual Section 303A FAQ A board that may have been a small circle of founders and venture investors has to be rebuilt around that standard before listing.
Independent directors staff committees that act as real checks on management. Under Nasdaq rules, the audit committee must have at least three independent members, all able to read and understand financial statements, with at least one qualifying as a financial expert.5The Nasdaq Stock Market. Nasdaq Rule 5600 Series – Corporate Governance Requirements The audit committee oversees the external auditor, the compensation committee sets executive pay, and the nominating committee controls who gets put forward as a board candidate.
Sarbanes-Oxley
Section 404 of the Sarbanes-Oxley Act requires management to assess the effectiveness of internal controls over financial reporting every year and include that assessment in the annual report.6U.S. Government Accountability Office. Sarbanes-Oxley Act – Compliance Costs Are Higher for Larger Companies but More Burdensome for Smaller Ones For larger public companies, an independent auditor must also attest to that assessment. Section 302 requires the CEO and CFO to personally certify the accuracy of each quarterly and annual filing. If those certifications are false, the officers face personal liability.
Shareholder Votes
Public shareholders elect directors, approve major transactions like mergers, and vote on equity compensation plans. Most participate through proxy ballots filed in advance of the annual meeting, and the company must distribute a detailed proxy statement covering candidates, pay, and every proposal on the ballot. Under the Dodd-Frank Act, public companies must also hold a non-binding advisory vote on executive compensation, known as say-on-pay. A company that loses that vote repeatedly faces pressure from institutional investors and proxy advisory firms to restructure its pay practices.7U.S. Securities and Exchange Commission. Investor Bulletin: Say-on-Pay and Golden Parachute Votes
Shareholders can also put items on the ballot themselves. SEC Rule 14a-8 allows any shareholder holding at least $25,000 for one year, $15,000 for two years, or $2,000 for three years to submit a proposal for inclusion in the proxy statement.8U.S. Securities and Exchange Commission. Shareholder Proposals Rule 14a-8 These proposals are advisory, but they create public accountability on issues management might otherwise ignore.
What the Company Has to Disclose From Now On
Regulation Fair Disclosure, or Reg FD, bars selectively sharing material nonpublic information with favored analysts or large shareholders. If an executive accidentally discloses something material in a private conversation, the company must promptly release that information publicly.9Securities and Exchange Commission. Selective Disclosure and Insider Trading
On top of that, the SEC mandates a fixed reporting calendar:
- The annual report on Form 10-K, filed after the fiscal year ends, contains full audited financial statements, management’s discussion and analysis, a detailed description of the business, and a comprehensive list of risk factors.10Investor.gov. Form 10-K
- The quarterly report on Form 10-Q, filed after each of the first three fiscal quarters, includes condensed financial statements that are reviewed but not fully audited.11eCFR. 17 CFR 240.15d-13 – Quarterly Reports on Form 10-Q
- The current report on Form 8-K, filed within four business days of a significant unscheduled event like a change in CEO, a major acquisition, or a bankruptcy filing.12Securities and Exchange Commission. Form 8-K Current Report Instructions
An independent audit firm reviews the annual financials and issues an opinion on whether they comply with Generally Accepted Accounting Principles. Running this infrastructure, external auditors, internal compliance staff, legal counsel, and controls technology, can cost millions of dollars a year even for smaller public companies.6U.S. Government Accountability Office. Sarbanes-Oxley Act – Compliance Costs Are Higher for Larger Companies but More Burdensome for Smaller Ones
What Changes for Founders, Employees, and Early Investors
For anyone holding equity before the IPO, the offering turns paper wealth into something that can be spent. But not right away. Nearly all pre-IPO shareholders sign lock-up agreements barring them from selling for a set period after the offering, most commonly 180 days.13U.S. Securities and Exchange Commission. Initial Public Offerings: Lockup Agreements The lock-up prevents a wave of insider selling from flattening the stock right after the debut. When it expires, the sudden supply of sellable shares often pushes the price down, which both insiders and new public investors should expect.
Even once the lock-up lifts, insiders live with permanent trading restrictions. Section 16 of the Securities Exchange Act requires officers, directors, and holders of more than 10% of the stock to report their holdings and every transaction to the SEC on Forms 3, 4, and 5.14U.S. Securities and Exchange Commission. Insider Transactions and Forms 3, 4, and 5 Form 4, covering changes in ownership, must be filed within two business days of a trade. Those filings are public, so every insider buy or sell is visible to the market almost immediately.
Insiders and holders of restricted stock must also comply with Rule 144 when selling. Rule 144 sets conditions on holding periods, volume, and manner of sale so that large insider dispositions don’t function as a disguised secondary offering.15U.S. Securities and Exchange Commission. Rule 144: Selling Restricted and Control Securities Most companies layer on internal trading policies, including blackout periods around quarterly earnings when insiders cannot trade at all.
The penalties for crossing these lines are serious. Civil penalties for insider trading can reach three times the profit gained or loss avoided from the illegal trade.16Office of the Law Revision Counsel. 15 U.S. Code 78u-1 – Civil Penalties for Insider Trading Criminal prosecutions can bring prison time.
For rank-and-file employees, the IPO converts illiquid stock options or restricted stock units into publicly tradable equity. The psychological relationship with the job shifts. Pre-IPO, employees knew their equity was worth something they could not touch. Post-IPO, they can check the stock price every five minutes, and companies that didn’t manage expectations well often see retention problems once the stock settles below its first-day pop.
Taxes on Your Pre-IPO Equity
The tax side of an IPO catches employees and founders off guard more often than any other part of the process. The treatment depends on the type of equity you hold, when you acquired it, and when you sell.
Restricted Stock Units
RSUs are the simplest. You owe ordinary income tax on the full fair market value of the shares when they vest and are delivered. If 1,000 RSUs vest when the stock trades at $40, you have $40,000 in taxable ordinary income that year, and your employer withholds taxes at vesting. Any gain above $40 per share when you later sell is a capital gain, with the rate depending on how long you held the shares after vesting.
Incentive Stock Options and the AMT Trap
Incentive stock options carry a tax benefit with a trap attached. If you exercise ISOs and hold the shares for at least one year after exercise and two years after the grant date, your entire profit is taxed as a long-term capital gain when you sell, a materially lower rate than ordinary income. The trap: when you exercise ISOs, the spread between the exercise price and the fair market value counts as income for alternative minimum tax purposes, even though you have not sold anything and have no cash in hand. For employees exercising large blocks of ISOs around an IPO when the stock is near its peak, the AMT bill can be enormous. More than a few people have faced six-figure tax bills on stock they later watched decline in value.
Nonqualified Stock Options
NSOs are simpler but less tax-advantaged. You owe ordinary income tax on the spread between the exercise price and the market price at the time of exercise, with payroll tax withholding on top. Any further gain when you sell is a capital gain.
Qualified Small Business Stock
Founders and very early investors may qualify for a powerful break under Section 1202 of the Internal Revenue Code. If the company was a qualifying C corporation with aggregate gross assets of $75 million or less when the stock was issued, and the shareholder holds for at least five years, up to 100% of the gain on sale can be excluded from federal income tax. The maximum excluded gain is the greater of $15 million or ten times the shareholder’s adjusted basis in the stock, for shares acquired after July 4, 2025. Shorter holding periods offer partial exclusions: 50% after three years and 75% after four years.17Office of the Law Revision Counsel. 26 U.S. Code 1202 – Partial Exclusion for Gain From Certain Small Business Stock For stock acquired before that date, the per-issuer limit is $10 million and the full exclusion requires a five-year hold with no partial tiers. The $15 million figure begins adjusting for inflation in 2027.
Section 1202 is a federal exclusion. Some states conform to it and some do not, which can meaningfully change the net savings. Anyone holding stock that might qualify should run the eligibility analysis well before selling.
What About Direct Listings and SPACs
A traditional underwritten IPO is no longer the only route to a public listing, but both common alternatives end at the same place. In a direct listing, the company skips underwriters, issues no new shares, raises no capital for itself, and has no lock-up period; existing shareholders sell directly to the public once trading opens. There is no price stabilization, no greenshoe, and no guaranteed institutional demand. In a SPAC transaction, a shell company goes public first, raises cash, and then merges with a private target within roughly two years, bringing the target public through the merger rather than its own IPO.18U.S. Securities and Exchange Commission. What Are the Differences in an IPO, a SPAC, and a Direct Listing? SPAC sponsors typically take a large equity stake, often 20%, which dilutes the merged company’s shareholders, and warrants issued to the SPAC’s IPO investors add more dilution.
Whichever path a company takes, once it is public it is subject to the same SEC reporting, governance requirements, and insider trading rules described above. The route in differs; the obligations on the other side are identical.