Initial coin offering (ICO)

An initial coin offering is a token sale run directly by the issuing project: a whitepaper, a published address or sale contract, a sale window, and tokens delivered automatically against payment. There is no underwriter, no exchange and no prospectus between the buyer and the project. That structure is what made the format fast in 2017 and what made it a securities problem afterwards.

The ICO's defining feature was the absence of an intermediary, and an intermediary is where disclosure, eligibility screening and record-keeping normally live. Removing it did not remove the obligations. It moved all of them onto the issuer, usually without the issuer noticing.

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Five steps and no third party anywhere in the chain. Every function an underwriter would normally perform was either automated or skipped.

How an ICO actually worked

The academic description is the most precise one available. Howell, Niessner and Yermack summarise the standard mechanics: a prospective buyer submits a purchase order by sending a payment to the issuer, usually in ether, and at the sale's conclusion the token contract automatically sends the purchased tokens to the blockchain addresses of successful buyers.¹

France's securities regulator, the AMF, documented the same sequence in its 2017 discussion paper as three stages: announcement, publication of a whitepaper, then sale, with tokens issued automatically in exchange for a transfer from the investor in the requested currency.² The AMF also recorded what the whitepaper typically contained, including the nature of the project, the members of the company or community, the token quantity held by promoters, the road map, the accepted settlement assets and the campaign duration.²

That is the whole apparatus. A document, an address and a smart contract. It settled globally, instantly, and to anyone with a wallet.

The whitepaper was the only disclosure document

In a registered offering, disclosure is a regulated artefact with liability attached to its contents. In an ICO it was a PDF, and the same academic study noted what was routinely missing from it: basic information about the issuer, with many whitepapers providing no contact address, no location, and nothing about the legal entity or individuals behind the sale.¹

That gap is the design lesson rather than a historical curiosity. A buyer who cannot identify the counterparty has no route to enforce anything, and an issuer who has not identified themselves has not reduced their exposure, only their credibility. Both sides lose something.

The habit worth keeping from the era is document-level scepticism, applied to your own materials first. Does working code exist, who holds the keys, which entity is party to the sale, and what happens to the funds if the road map does not land.

July 2017 is the date the format changed

The turning point is a specific document with a specific date. On 25 July 2017 the US Securities and Exchange Commission published a Report of Investigation under Section 21(a) of the Exchange Act concerning The DAO, finding that tokens offered and sold in that arrangement were securities.³ The immediate practical consequence was that the framing a project used for its own token did not settle the question.

The legal reasoning belongs elsewhere and this page will not reproduce it. The investment-contract analysis, the four prongs, and how classification runs transaction by transaction are covered properly on our Howey test and security versus commodity classification pages, and the answer for any specific offering is a question for counsel on your own facts.

What sits inside this page's lane is the structural point. Once the analysis attaches to the transaction rather than the label, an open global sale with no eligibility screening is exposure in every jurisdiction the buyers live in, and the issuer carries all of it.

One number from the enforcement record

The record is long and mostly repetitive. One case is worth stating precisely because of its scale. In September 2019 the SEC settled charges against Block.one over an unregistered ICO conducted from June 2017 to June 2018, with the company agreeing to pay a $24 million civil penalty and settling without admitting or denying the findings.⁴

A year-long open sale, a nine-figure raise, and a settlement that ended with a penalty rather than a rescission of the token. Different cases in the same period ended very differently, including with funds returned to buyers, which is the point: the outcomes were not predictable from the mechanics of the sale.

For a founder the takeaway is not the number. It is that the liability persisted for years after the sale closed and attached to a corporate entity that had already spent the proceeds building.

What replaced it

Three things, and most launches now use some combination. Private rounds under an exemption, documented with a token warrant or a simple agreement for future tokens, which moves the raise to eligible investors and separates it from the public distribution. Exchange-run sales, where a venue handles listing, payments and some vetting. And decentralised exchange launches, where the sale and the pool are the same event.

None of them is a workaround for the classification question. An exemption changes who may buy and what disclosure they receive. A venue changes who performs the screening. Neither changes what the token is or what buyers were told to expect, which is where the analysis actually runs.

The word ICO also survives loosely as a synonym for any public token sale, which causes real confusion in diligence. When someone says ICO now, ask which venue, which exemption, and which jurisdiction, because those three answers describe completely different structures.

If somebody proposes an ICO today

Four questions before anything else. Which legal entity is the seller and where is it organised. Which exemption or authorisation the sale relies on, named. Who is permitted to buy, and how that is enforced rather than asserted. And what the buyer receives in exchange, described as a right rather than an aspiration.

If any of the four has no answer, the proposal is not a fundraising plan. It is the 2017 structure with newer branding, and it carries the same open-ended exposure to the issuer that the enforcement record documents.

None of this is legal advice and none of it is a recommendation to buy, sell or hold anything. Whether a particular offering is a securities offering where it was sold turns on its own facts and belongs with your lawyers. What belongs here is the design consequence: a sale structure is a distribution decision, and distribution decisions are the ones that follow a project for years.

Common questions

What is an initial coin offering?

An ICO is a token sale run directly by the issuing project. The project publishes a whitepaper, opens a sale window and publishes an address or contract; buyers send payment and the contract delivers tokens automatically at the sale's conclusion.¹ No underwriter, exchange or prospectus sits between the two sides, which is both what made the format fast and what left every disclosure and eligibility obligation with the issuer.

Are ICOs illegal?

The format is not illegal as such, but an unregistered public sale that meets the definition of a securities offering carries the exposure of one. The SEC's July 2017 report on The DAO established that tokens sold in that arrangement were securities regardless of how the project described them.³ Whether a particular offering is a securities offering in a particular jurisdiction turns on its own facts and is a question for your lawyers.

What is the difference between an ICO, an IEO and an IDO?

The venue and who performs the screening. An ICO runs on the project's own site or contract, with buyers sending funds directly. An IEO runs on a centralised exchange, which handles listing, payments and some vetting. An IDO runs on a decentralised exchange, where the sale and the trading pool are effectively the same event. None of the three changes what the token legally is.

What happened to the projects that raised through ICOs?

Outcomes ranged widely and the enforcement record is the part with the clearest documentation. In one settled case the SEC charged Block.one over an unregistered ICO conducted from June 2017 to June 2018, and the company paid a $24 million civil penalty without admitting or denying the findings.⁴ Other matters in the same period ended with funds returned to buyers instead, so the mechanics of a sale did not predict its outcome.

See Token Launch Strategy for how this applies in practice.

Sources

Initial Coin Offerings: Financing Growth with Cryptocurrency Token Sales
Howell, Niessner and Yermack, European Corporate Governance Institute, 2019
Section 2.3 describes standard ICO mechanics and documents the disclosure gap, including whitepapers with no contact address or issuer identification.
Discussion Paper on Initial Coin Offerings (ICOs)
Autorite des marches financiers (France), 2017
A securities regulator's three-stage description of ICO mechanics, including automatic token issuance against transfer and the standard whitepaper contents.
Report of Investigation Pursuant to Section 21(a) of the Securities Exchange Act of 1934: The DAO, Release No. 34-81207
U.S. Securities and Exchange Commission, 2017
Published 25 July 2017. The finding that tokens offered and sold in the arrangement were securities. Cited here as a dated regulatory record; the legal analysis is treated on the Howey test page.
SEC Orders Blockchain Company Block.one to Pay $24 Million Penalty for Unregistered ICO, Press Release 2019-202
U.S. Securities and Exchange Commission, 2019
Settled charges over an ICO conducted from June 2017 to June 2018, with a $24 million civil penalty and no admission or denial of the findings.

Last reviewed 2026-08

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