Cardano (ADA) - the full guide

1. TL;DR

Cardano is a public blockchain whose native token is ADA. It launched in September 2017, is written in the Haskell programming language, and uses a proof-of-stake protocol called Ouroboros, so there is no mining. Its documentation describes a research-first approach based on a scientific philosophy. ^[1][2][23]

Cardano is developed by several independent organizations rather than one company. The official site lists the Cardano Foundation, EMURGO, Input Output (IOG), Intersect and PRAGMA. IOG was founded in 2015 by Charles Hoskinson. ^[13][29]

ADA has a hard cap of 45 billion. At the time of writing the chain reported about 38.92 billion ADA already issued and about 6.08 billion still in the reserve that pays staking rewards. The on-chain treasury held about 1.37 billion ADA. ^[22][23]

The network moved to community governance in 2024 and 2025. Holders can delegate voting power to a delegate representative (DRep), and treasury spending is decided by on-chain votes. At the time of writing, 70 treasury withdrawals had been enacted through that process. ^[4][5][25]

Usage is modest next to the largest smart contract chains. DefiLlama showed about 68 million dollars of total value locked on Cardano, and cardano.org reported about 773 thousand transactions in 30 days. The project has also been criticized for slow delivery. ^[39][13][34]

Before holding ADA, know four practical points. Use a Shelley address that starts with addr1, mind the minimum ADA that every output must carry, understand that staking does not lock your coins, and withdraw only to the Cardano network. ^{[9][10][8][11]}

2. Live stats

The figures below update automatically from public market data; everything else on this page was checked at the time of writing.

3. What problem does it try to solve

Early blockchains were built quickly and then patched. Bitcoin proved that a ledger without a central owner could work, and Ethereum added programmable contracts. Both ran into the same trade-offs: energy-hungry mining in Bitcoin's case, upgrades that are hard to coordinate, and fees that can spike when many people use the network at once.

Cardano's founders asked a different question: what if a blockchain were designed more like safety-critical software? The documentation says the platform was designed and verified by engineers and academic experts, is fully open source, and focuses on sustainability, scalability and transparency. ^[1]

In practice, this shows up as four design choices. The consensus protocol has published security proofs. The ledger uses a model in which the outcome of a transaction can be checked before it is sent. Tokens are a feature of the ledger itself rather than a smart contract. And the rules for changing the network are meant to end up in the hands of ADA holders, not the original developers. ^[2][7][8][5]

Think of the difference between a city that grew street by street and one that was planned from a master drawing. The planned city may be orderly, but it can also be slow to build and hard to adjust once people live in it. Cardano's history, covered in the next chapters, contains examples of both.

A fair way to read the project is to ask two separate questions. First, does the technology do what its documentation says? That can be tested. Second, does careful engineering turn into real users and lasting demand for ADA? That depends on developers, businesses and users choosing the network, and it is what chapters 7 and 12 examine.

4. History, founders, organization and governance

Founding and the three original entities

The Cardano site says ADA was distributed in four stages between October 2015 and January 2017, and Wikipedia gives 27 September 2017 as the launch date of the network. Genesis data read from the chain shows a system start on 23 September 2017 (UTC). We use "September 2017". ^[21][31][23]

Three entities were involved from the start. IOHK (now IOG) did the engineering, EMURGO was set up for commercial adoption, and the Cardano Foundation, based in Switzerland, was to promote the ecosystem. The official genesis page lists all three as recipients of a development pool. ^[21][31]

IOG's own page says it was founded in 2015 by Charles Hoskinson, employs more than 600 people in over 50 countries and now lists Cardano as one of its ecosystems. EMURGO describes itself as a co-founding entity focused on commercial adoption and asset tokenization. ^[29][30]

Roadmap eras

The documentation organizes Cardano's history into eras named after historical figures. Byron was the launch period with federated block production. Shelley, in July 2020, handed block production to community stake pools. Goguen added native tokens (Mary) and smart contracts (Alonzo). Basho focused on performance, including the Vasil upgrade. Voltaire is the governance era. ^[3]

Each era arrived as a hard fork, a coordinated software upgrade in which every node must switch. In February 2023 the Valentine upgrade added signature primitives to the smart contract system. ^[3]

The Chang and Plomin upgrades

Voltaire began with the Chang upgrade, completed in its first stage in August 2024. It introduced the Conway ledger era and a governance system defined in a proposal called CIP-1694. In stage one, delegates could register, an interim constitution and an interim constitutional committee were put in place, and most votes were limited to stake pool operators and the committee. ^[4]

The second stage, renamed Plomin, enabled full on-chain decision making, including treasury withdrawals. The documentation also says a Constitutional Convention took place on 4-6 December 2024, where 95 percent of elected delegates agreed to the draft constitution. ^[4]

The chain data adds detail. At the time of writing, the on-chain record showed a hard fork initiation that was proposed in epoch 529 and enacted in epoch 537, a constitution enacted in epoch 542, and a later constitution update enacted in epoch 609. Epochs last five days, so these are separated by months. We did not convert epoch numbers into calendar dates because the sources do not do so. ^[25][23]

How governance works

Three bodies take part. Delegate representatives (DReps) are ADA holders, or people holders delegate to, whose votes are weighted by the ADA delegated to them. Stake pool operators vote on certain actions. A constitutional committee checks that actions follow the constitution. The documentation says every governance action must be ratified by at least two of the three bodies, and treasury withdrawals need the committee and the DReps. ^[5]

The parameters show how demanding this is. The ledger sets a 75 percent DRep threshold to change the constitution, 67 percent for treasury withdrawals, a deposit of 100,000 ADA to submit a governance action, and a six-epoch lifetime for each action. The committee had 7 members at the time of writing, with a two-thirds quorum. ^[24][28]

By count, activity is real. The chain showed 158 governance actions in total, of which 70 treasury withdrawals were enacted and 33 expired, and 1,048 registered DReps. Enacted treasury withdrawals added up to about 804 million ADA by our own sum of the on-chain amounts. ^[25][27]

Funding and who pays the developers

Treasury money is how the organizations behind Cardano are now paid. In April 2026 The Block reported that IOG had put forward nine treasury proposals for 2026 totalling just under half of the previous year's request, plus a separate request of 62.1 million ADA for ongoing network maintenance, with voting open until 24 May 2026. We did not verify the final outcome of those votes. ^[34]

5. The technology, explained simply

Ouroboros: choosing block producers by stake

In a proof-of-work chain, computers compete to solve puzzles. In Ouroboros, time is divided into short slots, and the protocol picks a stake pool to produce the block for each slot, in proportion to the stake that pool controls. The documentation calls it "the first provably secure proof-of-stake protocol." ^[2]

A lottery is a fair comparison. Every ADA in a pool is a ticket, and the draw happens privately, so nobody can predict the winner of a future slot and attack that pool in advance. This private choice is a feature of the Praos version of the protocol. ^[2]

On the network, the genesis file shows one-second slots, an active slot coefficient of 0.05 and epochs of 432,000 slots. By our arithmetic that is a block roughly every 20 seconds on average and an epoch every five days. ^[23]

Finality on Cardano is probabilistic. The documentation says a transaction becomes immutable once its depth exceeds 3k/f slots, but that a transaction is treated as confirmed once the probability of reversal is low enough. The page does not give a confirmation time, and the security parameter k is 2,160 in the genesis data, so the hard bound is long while practical confirmation depends on the value at stake. ^[20][23]

The eUTXO model

Bitcoin tracks coins as separate outputs, like banknotes in a wallet, and calls them UTXOs. Ethereum keeps an account balance, like a bank account. Cardano extends the banknote idea with an "extended UTXO" model in which an output can carry a script and attached data. ^[7][18]

The documentation draws two conclusions. First, "the success or failure of transaction validation depends only on the transaction itself and its inputs," so a transaction can be checked before it is sent and fees can be predicted exactly. Second, a transaction can still fail if someone else spends one of its inputs first, and if all inputs are still unspent it is guaranteed to succeed. ^[7]

The trade-off is design effort. When many users need to touch the same piece of shared state, such as a busy trading pool, developers have to split that state across outputs or queue requests. We did not find an official source quantifying this limit, so we describe it as a design constraint rather than a measured one. ^[7]

Fees

The minimum fee follows a formula of the form a times transaction size plus b, where both are protocol parameters. The live parameters at the time of writing were 44 lovelace per byte plus a flat 155,381 lovelace, and a lovelace is one millionth of an ADA. A transaction of about 300 bytes therefore costs roughly 0.17 ADA by our calculation. ^[24][51]

The fee is not paid to the block producer alone. The documentation says fees are pooled and distributed to all pools that produced blocks in the epoch. ^[51]

Native tokens and smart contracts

On Cardano, creating a token does not need a smart contract. The documentation says the ledger handles all token functions, which lowers the risk of manual errors. The cost is that every output carrying tokens must also carry a minimum amount of ADA, covered in chapter 14. ^[8]

Real smart contracts are written in Plutus, a Haskell-based language, or in Aiken, a newer language designed only for on-chain validators that compiles to the same low-level code. Aiken is described as easier for developers who do not know functional languages. ^[18][19]

Scaling work: Hydra, Mithril and Leios

Hydra is a layer 2 design. A small group opens a "head," a mini ledger that processes transactions off-chain using the same ledger rules and posts only the final result to the main chain. The Hydra site showed version 2.4.1 at the time of writing. Neither page we read states limits or mainnet usage levels, so we make no claim about them. ^[15][16]

Mithril is a stake-based multi-signature scheme that produces certified snapshots of the chain. Its first use is letting a new node start from a snapshot instead of checking all history. ^[17]

Leios is described in the documentation as research and development: a high-throughput layer on top of the base protocol. In April 2026 The Block reported a testnet target of June 2026 and a mainnet target of the end of 2026, with IOG's public tracker showing about 24 percent testnet progress. We could not verify progress after that report, so treat Leios as unfinished at the time of writing. ^[2][34]

6. The token

Supply and distribution

The genesis data from the chain shows a maximum supply of 45 billion ADA. At the time of writing, the chain reported 38.92 billion ADA issued in total, 36.80 billion ADA in circulation and 6.08 billion ADA remaining in the reserve. Issued plus reserve equals 45 billion. ^[23][22]

From those figures, the three founding entities received about 16.7 percent of the launch supply, and the remaining 13.89 billion ADA of the 45 billion cap was held back for staking rewards. This subtraction is our calculation. ^[21][23]

Where new ADA comes from

New ADA is not mined. Each epoch, a fixed share of the remaining reserve is released into the rewards pot. The documentation sets this expansion rate at 0.3 percent per epoch and says the treasury takes a fixed 20 percent of the pot before staking rewards are paid. Fees add to the pot. The live values at the time of writing, 0.003 and 0.2, match. ^[6][24]

Because the share is taken from a shrinking reserve, new issuance slows over time. The documentation projects a reserve half-life of roughly four to five years. The sum can never pass 45 billion. ^[6]

What ADA is used for

ADA pays transaction fees, backs the security deposits for pools and stake keys, and is the unit that votes in governance, since DRep voting power is counted in ADA. It is also the minimum balance that every token output must carry. ^[24][5][8]

The treasury

About 1.37 billion ADA sat in the treasury at the time of writing. The treasury receives 20 percent of each epoch's rewards pot, and it can only be spent by an enacted governance action. This is unusual transparency: the balance and each withdrawal are visible on-chain. It also means the people who vote on spending are partly those who receive it. ^[22][5][25]

Staking in one paragraph

Holders can delegate their ADA to a stake pool without moving it. The cardano.org site says delegating does not move ADA out of the wallet and there is no lock-up or minimum, and that there is no slashing. The documentation adds that you can spend delegated ADA at any time. A refundable deposit, 2 ADA at the time of writing, registers the stake key. ^[13][11][24]

7. Real adoption

We separate three kinds of evidence: live production usage that can be checked, announcements and pilots, and narratives we could not verify.

8. The ISO 20022 connection

ISO 20022 is a messaging standard for structured payment data used by banks and payment systems. It defines message formats, not blockchains, so the idea that a public ledger can "be compliant" is not a recognized technical status. ^[49]

We found no statement from the Cardano Foundation, IOG or ISO confirming that ADA or the Cardano protocol is ISO 20022 compliant. A discussion thread on the Cardano forum notes that ISO has no certifying authority for coins, and another argues that the claim is a misunderstanding of how the standard works. ^[48][49]

The claim circulates because of secondary sources: an infographic shared by Charles Hoskinson, a category on the CoinMarketCap website, and crypto media lists. These show that the claim is widespread, not that it has been verified. ^[48]

We did not find a production deployment that maps ISO 20022 messages onto Cardano transactions, so we treat any such claim as unverified. For the general explanation, see the ISO 20022 guide.

9. Ecosystem and competitors

Cardano's ecosystem

At the time of writing, cardano.org curated 103 apps. Its top apps by 30-day transactions were Minswap (127,400, a decentralized exchange), Dano Finance (42,900, lending) and Wayup (6,000, an NFT marketplace). Governance tools, wallets and block explorers such as Cardanoscan are also part of the ecosystem. ^[13]

Several organizations work on the network. The official site lists the Cardano Foundation, EMURGO, IOG, Intersect and PRAGMA. This is a real strength compared with chains run by one company, but it also means roadmap decisions involve negotiation and the treasury. ^[13]

How it compares

This table is a general orientation based on public design descriptions and is not individually sourced. See the comparison page for sourced figures.

On the numbers we could verify, Cardano's DeFi footprint was about 68 million dollars of TVL at the time of writing, which places it far from the leading smart contract chains. Its argument is not size but design: formal methods, predictable fees and community governance. Whether those translate into growth is open. ^[39]

Cardano and other chains

Cardano also relates to other networks. Midnight is a separate chain whose token NIGHT lives on Cardano. DefiLlama listed a bridge product among the larger protocols by value on Cardano, which means some activity depends on moving assets across chains and carries bridge risk. ^[33][41]

10. Regulation and legal history

The 2023 SEC complaints

In June 2023 the US Securities and Exchange Commission (SEC) sued the exchanges Binance and Coinbase. A Grayscale annual report states that in those complaints the SEC "asserted that several digital assets were securities, including ADA, MATIC and SOL." Grayscale's manager said it continued to believe those assets were not securities. ^[42]

IOG publicly disputed the claim that ADA is a security, according to crypto media coverage. In November 2023 the SEC also sued Kraken, and that complaint again lists ADA among the assets it alleged were securities, claiming ADA was offered and sold as an investment contract. ^[46][45][53]

What happened next

The SEC dismissed its Coinbase case by joint stipulation on 2025-02-27 and said it did so in its discretion and not because of a ruling on the merits. According to its litigation releases LR-26278 and LR-26316, it dismissed the Kraken case on 2025-03-27 and the Binance case on 2025-05-29, both with prejudice. The agency said none of these decisions reflected its view on other cases. ^[43][44][54]

No court ruled whether ADA is a security; the SEC withdrew from the cases that named it. The gap was then filled by the regulator rather than a court: on March 17, 2026 the SEC published an interpretive release, with guidance from the CFTC and effective March 23, 2026, that lists Cardano (ADA) among sixteen examples of "digital commodities", which it says are not themselves securities. XRP, XLM and HBAR are on the same list. The release is an interpretation, not a statute, does not replace the Howey test, and may be revised. At the time of writing we found no 2026 enforcement action naming ADA. ^{[42][43][44][52]}

ETF status

Grayscale filed a Form S-1 for the Grayscale Cardano Trust ETF on 2025-08-29. On 2026-08-07 it asked the SEC to withdraw the registration statement (Form RW), saying it "does not intend to proceed with the planned distribution" of the trust's shares. This is a voluntary withdrawal, not an SEC rejection. Bitcoinist reported that another filing remains possible. We found no US spot ADA ETF trading at the time of writing. ^[55][47]

Other jurisdictions

In the EU, ESMA's interim MiCA register lists white papers for ADA drawn up by third parties: the Liechtenstein exchange LCX (2025-03-18) and the German data provider Crypto Risk Metrics (notified to BaFin, 2026-04-27). These are disclosure documents, not regulator approvals or classifications. ^[56] We did not verify ADA's status in the UK or Israel for this edition. Check the current rules of your own country and of any exchange you use before buying.

11. Key risks

• Delivery risk. The scaling roadmap has repeatedly been questioned. Critics argue Cardano has fallen behind on scaling, and Hoskinson has called the claim a "false narrative." IOG's own tracker showed about 24 percent testnet progress on Leios in April 2026 against an end-2026 mainnet target. ^[35][34]
• Funding concentration. Core development is paid from the treasury, which holders vote on. IOG's request was cut roughly in half for 2026, and a rejected budget could slow work. ^[34]
• Governance concentration. About 28 percent of circulating ADA is delegated to "always abstain," and active participation is much smaller than the number of holders. A few large delegates could carry votes. ^[27]
• Adoption risk. About 68 million dollars of TVL and 71 million dollars of stablecoins is small for a top-tier network, and much of the activity is concentrated in a few apps. ^[39][40][41]
• Regulatory uncertainty. ADA was named as a security in SEC complaints that were later dropped without a ruling. Its current US status as a "digital commodity" rests on a 2026 SEC interpretation, not on a statute or court ruling, and a future Commission could revise it. A US spot ETF filing was withdrawn. ^{[42][43][52][55]}
• Technical constraints. The eUTXO design needs developers to manage shared state carefully, and every token output needs a minimum ADA deposit. Smart contract bugs and bridge failures are risks of any chain. ^[7][8]
• Claims versus evidence. Some projects tied to Cardano, such as the Ethiopia credential plan, were announced at much larger scale than the evidence we could verify. ^[36][38]
• Personal risks. Wrong-network transfers, phishing, lost recovery phrases and exchange failures are the most common ways individuals lose funds.

This is educational content, not investment advice.

12. Bull case vs bear case

The bull case

Supporters point to a network that has run since 2017, uses a protocol with published security proofs, and keeps fees predictable because a transaction can be validated before it is sent. They add that the supply is capped at 45 billion with a transparent treasury, that governance is on-chain with 70 treasury withdrawals already executed, and that development is shared among several independent organizations. They also note that staking has no lock-up and no slashing, and that Midnight and a growing set of tools extend the ecosystem. Under this view, careful engineering and community governance would attract developers over time. ^{[2][7][23][25][5][13][32]}

The bear case

Skeptics respond that usage is small. TVL of about 68 million dollars and 71 million dollars of stablecoins are far below the leading chains, and the number of transactions attributed to showcased apps is a fraction of the total. They point to slow delivery, such as the Leios schedule, and to a treasury in which funding recipients and voters overlap. Governance participation is thin, with a large share of voting power parked in "always abstain." Its US status rests on a revisable 2026 SEC interpretation rather than a court ruling, and a spot ETF filing was withdrawn. The design also leans on a few organizations to ship core software. ^{[39][40][13][34][27][42][52][55]}

Both cases rest on verifiable facts; they differ on whether engineering quality and governance will turn into usage and lasting demand for the token. The reader decides.

What both sides can monitor

Several things can be tracked over time. One is whether Leios reaches mainnet and what throughput it delivers. Another is treasury budgets and the share of DRep stake that votes. A third is TVL, stablecoin supply and app transactions. A fourth is any new ETF filing or any change to the SEC's 2026 classification. Finally, evidence of production use for credential and identity projects would matter. ^{[34][27][39][47][36]}

13. Scorecard

The scores follow the rubric used for every coin on this site; the reasoning for each category appears in the card.

14. How to buy and store

Before the exchange and wallet list, five Cardano-specific pitfalls.

1. Use a Shelley address (addr1) and know the legacy Byron format. Cardano has two address families. Modern Shelley addresses are bech32 strings; the human-readable prefix is addr on mainnet and addr_test on a test network, so a mainnet address begins with addr1. Legacy Byron addresses are encoded in Base58 and are a different format. The documentation says Shelley kept supporting Byron-era addresses, but only base and pointer addresses carry staking rights. If you want to stake, use a base address. Check that an exchange accepts the address type you plan to send from or to, and never type an address by hand. ^[10][9]

2. Every output needs a minimum amount of ADA. On Cardano you cannot hold tokens without ADA next to them. The documentation says outputs cannot contain only custom tokens, and that sending tokens always includes the minimum ADA in the same output. More token types in one output raise the minimum, and splitting tokens across outputs needs more total ADA. The live parameter at the time of writing was 4,310 lovelace per byte of output, so each extra 100 bytes adds about 0.43 ADA by our calculation. A simple wallet-to-wallet send of tokens often needs around 1 to 2 ADA to travel with them, which is our estimate; your wallet shows the exact amount. If you hold less ADA than a token output needs, the transaction will be rejected. ^[8][24]

3. Non-custodial staking from a cold wallet. You can stake ADA while it stays in a non-custodial wallet, including a hardware wallet. The cardano.org site states that delegating does not move ADA out of your wallet, there is no lock-up or minimum, and there is no slashing: the protocol cannot take your ADA as a penalty. Trezor's guide adds that staking never locks your ADA, that it needs a refundable 2 ADA deposit to register the stake key, that staking becomes active about 10 days after the transaction confirms, and that rewards arrive every 5 days. ^[13][11][14]

Two cautions. First, Cardano blocks reward claims unless the stake key has a vote delegation to a DRep, which Trezor Suite sets by default, so check this if rewards seem stuck. Second, "no lock-up" refers to the protocol; services that offer "liquid staking" tokens or staking on an exchange add their own custody and smart contract risks, which we did not evaluate. Delegating from a cold wallet is a signing action: the wallet signs a delegation certificate, and the funds stay under your keys. ^[14][13]

4. Cardano network only, and no memo. When withdrawing from an exchange, select the Cardano network. Do not choose a wrapped or bridged version on another chain unless you intend to use it there. Cardano addresses do not use a memo or destination tag in normal exchange withdrawals, because the address format defined in CIP-19 has no memo field. If a deposit page asks for one, stop and read the exchange's instructions. Wrong-network transfers are usually irreversible. ^[10]

5. Where to keep it. Leaving ADA on an exchange is a custodial arrangement: the exchange holds the keys and you hold a claim on it. Moving it to your own wallet means you hold the private key and the seed phrase, and nobody can recover them for you. A hardware wallet keeps the keys on a separate device. This is general safety information, not a recommendation of any product. The list below shows the verified options. ^[14]

Finally, confirm the first and last characters of the address against what the exchange displays, and use a block explorer such as Cardanoscan to confirm that your test payment arrived before sending the rest.

15. Sources

16. Live chart

Price data comes from a public market feed and is shown for context only.