Sui is a Layer 1 blockchain for smart contracts. It was created by Mysten Labs, a company founded in 2021 by engineers who had worked on Meta's Diem blockchain project and its Novi wallet. The Sui mainnet launched on May 3, 2023. Its native token is SUI. The project's own overview is on the Sui website.
Two design choices separate Sui from most other chains: it stores everything as objects instead of account balances, and its contracts are written in a language called Move.
The Move Language
Move was first written for Diem. It was designed for one purpose, which is handling digital assets safely. In Move, an asset is a resource. The language rules prevent a resource from being copied or silently discarded. It can only be moved from one owner to another.
This removes some classes of bugs that have caused large losses on other chains. Reentrancy, where a contract is called again before it finishes updating its balances, is much harder to write by accident in Move.
Sui uses its own version of the language, often called Sui Move. Aptos, another chain started by former Diem engineers, also uses Move but with a different data model. The two are related, and code does not transfer between them without changes.
The Object Model
On Ethereum, a token balance is a number stored inside a contract. On Sui, each coin, NFT or game item is its own object with a unique ID, a version and an owner. The Sui documentation describes the model in full.
Objects fall into two broad groups:
- Owned objects: controlled by one address. A simple payment only touches objects the sender owns.
- Shared objects: usable by anyone, such as a trading pool on a decentralized exchange.
The difference matters for speed. Every transaction must declare up front which objects it will touch. Transactions that touch different objects cannot conflict, so validators can execute them at the same time. This is called parallel execution. Chains that process transactions one after another cannot do this as easily.
Consensus and Staking
Transactions that involve shared objects need to be ordered, because two people may try to use the same pool at once. Sui orders them with a consensus protocol called Mysticeti, which replaced the earlier Narwhal and Bullshark design in 2024. Under normal conditions, transactions are final in under a second.
Sui is secured by delegated Proof of Stake. SUI holders delegate tokens to validators and share in the rewards. The validator set and the stake amounts are updated once per epoch, which lasts about 24 hours.
The SUI Token
SUI has a fixed maximum supply of 10 billion tokens. Not all of them are in circulation. Large allocations for early contributors, investors and the community reserve are released over several years, so circulating supply keeps growing for some time.
The token is used to pay gas fees, to stake with validators and to take part in governance votes. Fees are counted in MIST. One SUI equals one billion MIST.
Sui charges two kinds of fees. The computation fee pays for executing the transaction. The storage fee pays for keeping data on-chain and goes into a storage fund that compensates future validators for holding that data. If a user later deletes the object, most of the storage fee is refunded.
What Runs on Sui
- Decentralized exchanges such as Cetus, and the DeepBook order book that other apps can build on
- Lending markets and liquid staking protocols
- Games that represent in-game items as objects owned by players
- SuiNS, a name service that maps addresses to readable names
- Bridges that connect Sui to Ethereum and other chains
Sui also offers zkLogin, which lets a user create a wallet by signing in with an existing account such as Google, without writing down a seed phrase first.
Sui vs Aptos
The two chains are often compared because of their shared Diem roots. Aptos keeps data under accounts, closer to the Ethereum approach, and runs transactions in parallel by guessing which ones will not conflict and re-running the ones that do. Sui asks each transaction to declare its objects in advance. Both chains remain smaller than Ethereum and Solana by most usage measures.
Risks to Understand
- Outages: the network stopped producing blocks for about two hours in November 2024. Younger chains have less of a track record under stress.
- Application exploits: in May 2025, the Cetus exchange was drained of more than $200 million through a bug in its contract code. Move reduces some bug types but does not remove them.
- Validator power: after the Cetus exploit, validators froze a large part of the stolen funds, and a governance vote later returned them. Users were helped, but it showed that a coordinated validator set can block specific transactions.
- Supply growth: scheduled token releases add to circulating supply for years.
- Competition: Sui competes with Solana, Aptos and Ethereum Layer 2 networks for the same developers and users.
Common Mistakes
A common mistake is comparing market cap without checking how much of the 10 billion supply is circulating. Another is assuming Move contracts are safe by default. Audits and time in production still matter. A third is sending SUI to an exchange on the wrong network, since wrapped versions exist on other chains.
Nothing in this article is financial advice.
Key Sui Facts
- Developer: Mysten Labs, founded in 2021
- Mainnet launch: May 3, 2023
- Language: Move (Sui version)
- Consensus: delegated Proof of Stake with Mysticeti
- Maximum supply: 10 billion SUI
- Smallest unit: MIST, one billionth of a SUI
Track on CoinMarketGuy
The Sui price page shows the live SUI price, market cap, circulating supply and chart. The DEX page lists active liquidity pools with their volume and liquidity, and the trending page shows which coins are being searched most.