[Crypto projects](https://revain.org/projects/) › Qtum

# Qtum (QTUM): how it works, supply and reviews

## Key facts

- **Ticker**: QTUM
- **Network**: own blockchain
- **Official site**: [qtum.org](https://qtum.org/)
- **Source code**: [github.com/qtumproject/qtum](https://github.com/qtumproject/qtum/)

Data: CoinGecko (trading activity) and CoinPaprika (links), 2026-10-27. Only projects that still trade with meaningful volume are listed.

## What is Qtum

Qtum (QTUM) is an open-source proof-of-stake blockchain that combines Bitcoin's UTXO transaction model with Ethereum Virtual Machine smart contracts, linked by an Account Abstraction Layer. Network parameters such as block size and gas prices can be changed on-chain through its Decentralized Governance Protocol without a hard fork.

## Network and consensus

| Parameter | Details |
|---|---|
| Type | Layer-1 blockchain using Bitcoin's UTXO model with EVM smart contracts |
| Consensus | Proof of stake; any user can stake, with no minimum amount, voting or masternodes |
| Block time | 32 seconds; 2 MB blocks |
| Smart contracts | Yes, EVM-compatible; most Solidity contracts work without a special compiler |
| Programming language | Solidity |

## Supply and issuance

| Parameter | Details |
|---|---|
| Maximum supply | 107,822,406 QTUM |
| Initial distribution | 100 million QTUM created in the first 5,000 blocks; 51% sold to the public in March 2017, 20% to founders, team and private investors, 29% for business development, research and community |
| Staking rewards | Stakers receive a block subsidy plus transaction and gas fees |
| Halving | Block subsidy halves about every 4 years, seven times in total, then stops |

## What QTUM is used for

- Staking to produce blocks and earn rewards.
- Paying transaction fees and gas for smart contracts.
- Taking part in on-chain governance through the Decentralized Governance Protocol.

## Who develops and governs Qtum

- **Foundation**: Qtum Chain Foundation, a non-profit company registered in Singapore in November 2016
- **Governance**: On-chain Decentralized Governance Protocol (DGP) plus off-chain governance by the Foundation
- **Founders**: Three co-founders lead the Foundation as CEO, CTO and lead developer
- **Open source**: Yes; Qtum Core is the reference implementation

## History

| Date | Event |
|---|---|
| November 2016 | Qtum Chain Foundation registered in Singapore. |
| March 2017 | Public sale of 51 million QTUM (51% of the initial supply). |
| 17 October 2019 | Mainnet upgraded to Qtum 2.0 with its first hard fork. |
| 24 February 2020 | New Qtum whitepaper published. |

## Security and audits

- Block rewards are shared with nine previous block producers and mostly paid with a 500-block delay, to make spam-contract attacks costly.
- Qtum Core supports reproducible builds with Guix that anyone can verify.

## Risks and caveats

- The developers describe Qtum Core as beta software with no warranties of security or stability.
- Network parameters such as block size and gas prices can be changed through on-chain governance without a hard fork.
- 20% of the initial supply went to the founding team, development team and private investors.

## Official links

- Website: [qtum.org](https://qtum.org/)
- Whitepaper: [qtumorg.s3.ap-northeast-2.amazonaws.com/Qtum_New_Whitepaper_en.pdf](https://qtumorg.s3.ap-northeast-2.amazonaws.com/Qtum_New_Whitepaper_en.pdf)
- Docs: [docs.qtum.info/qtum-documentation](https://docs.qtum.info/qtum-documentation/)
- Source code: [github.com/qtumproject/qtum](https://github.com/qtumproject/qtum)
- Block explorer: [qtum.info](https://qtum.info)

## Questions and answers

**What is Qtum?**

Qtum is a proof-of-stake blockchain that combines Bitcoin's UTXO model with Ethereum-compatible smart contracts.

**Who is behind Qtum?**

Qtum is supported by the Qtum Chain Foundation, a non-profit registered in Singapore in November 2016 and led by three co-founders.

**What is the maximum supply of QTUM?**

The total supply is 107,822,406 QTUM: 100 million created at launch plus block rewards that halve until they stop.

**How does Qtum reach consensus?**

Qtum uses proof of stake with 32-second blocks. Any holder can stake, with no minimum amount.

## Sources

- [CoinGecko — Qtum](https://www.coingecko.com/en/coins/qtum)
- [CoinPaprika — Qtum](https://coinpaprika.com/coin/qtum-qtum/)
- [Qtum — About](https://qtum.org/about)
- [Qtum — Technology](https://qtum.org/tech)
- [Qtum — New Whitepaper (24 February 2020)](https://qtumorg.s3.ap-northeast-2.amazonaws.com/Qtum_New_Whitepaper_en.pdf)
- [Qtum Core — README](https://raw.githubusercontent.com/qtumproject/qtum/master/README.md)

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Page updated: 2026-10-28

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Source: https://revain.org/projects/qtum/