How to Read an S-1 IPO Filing, Section by Section
An S-1 is the registration statement a US company files with the SEC before an IPO. It is free on EDGAR, and it holds the audited numbers, the risks and the terms of the sale that no news story has.
You do not need to read all of it. Start with the risk factors, the use of proceeds, the dilution table and the financial statements, in that order.
What is in an S-1, section by section?
| Section | What it tells you | What to look for |
|---|---|---|
| Prospectus summary | The company's own pitch and a table of key numbers | Revenue, growth and net loss, plus the share counts before and after the offering |
| Risk factors | What the company thinks could go wrong | Customer concentration, dependence on one product, legal issues, control by a few holders |
| Use of proceeds | Where the money raised goes | Whether the company gets it, or existing holders do |
| Dilution | What new buyers pay against book value | The gap between your price and the net tangible book value per share |
| Management's discussion (MD&A) | Management's explanation of the results | Why revenue and costs moved, and the cash runway |
| Principal and selling stockholders | Who owns the company and who is selling | Insiders' stakes and any shares sold in the offering |
| Financial statements | Audited income statement, balance sheet and cash flow | Multi-year trends and the auditor's opinion |
| Underwriting | The banks, fees and lock-up terms | How long insiders are locked up |
Where do you find an S-1?
On the SEC's EDGAR system, free and without an account. Search the company by name, then filter the filing list by form type.
| Form | What it is |
|---|---|
| S-1 | The registration statement of a US company |
| F-1 | The same for a foreign private issuer listing in the US |
| S-1/A or F-1/A | An amendment, often with the price range and updated numbers |
| 424B4 | The final prospectus, filed after the IPO prices |
A company can submit a draft to the SEC confidentially and need not file publicly until at least 15 days before the roadshow, so a reported filing may not be on EDGAR yet, as with Anthropic. Haynes Boone explains the policy.
What do you check first in an S-1?
- Revenue growth and net loss. Read the multi-year table in the summary and the financial statements. A fast-growing company with large losses is a different bet from a profitable one.
- Who receives the money. The use of proceeds says whether shares are new (the company gets cash) or sold by existing holders (the company gets none).
- The dilution table. It compares the price new buyers pay with book value, and shows how many shares exist before and after.
- Pay in stock. Large stock-based compensation expands the share count over time; see the stock-based compensation entry.
- Lock-up terms. The underwriting section says when insiders can sell.
The risk factors section is long and mostly generic, so look for the specific items: one customer that makes up a large share of sales, a product the company depends on, a legal case.
Why does it matter whether shares are new or sold by existing holders?
New shares bring cash into the company and add to the share count. Shares sold by existing holders give them cash and the company none. A filing can mix both, so the split tells you what the IPO is for.
Illustrative numbers, not a real company. The use of proceeds section states the real split.
S-1 FAQ
What is the difference between an S-1 and an F-1?
An S-1 is the IPO registration form for US companies. An F-1 is the equivalent for foreign private issuers listing in the US. Both contain the prospectus and are read the same way.
Is an S-1 the same as a prospectus?
The S-1 contains the prospectus. The final version, with the price, is filed as form 424B4 after the IPO prices.
Does the S-1 show the IPO price?
Not at first. Early versions leave the price blank or give a range. Amendments update it, and the final price appears in the 424B4 prospectus.
Why can I not find an S-1 for a company reported to be filing for an IPO?
A company can submit a draft to the SEC confidentially. Nothing appears on EDGAR until it files publicly, which must happen at least 15 days before the roadshow begins.
Once a company lists, its numbers move to the 10-K and quarterly reports, which feed the stock pages on this site; the 13F guide does the same for investors' holdings. For the whole process, see the IPO guide. Educational content only, not investment advice.