0x is an infrastructure protocol that allows users to easily trade ERC20 tokens and other assets on the Ethereum blockchain without relying on centralized intermediaries like traditional cryptocurrency exchanges.
0x achieves this decentralized exchange functionality using a collection of open-source, publicly auditable smart contracts that work together to produce a flexible, low-friction trading protocol that developers can easily weave into their products.
The protocol is powered by an ERC20 utility token known as ZRX. Nodes that (also known as relayers) host an off-chain order book and offer user-facing applications that present this information and allow users to make, fill and cancel transactions are paid in ZRX tokens (as trading fees). ZRX can also be used to participate in platform governance, helping holders suggest and vote on changes to the protocol.
In 2019, 0x announced an overhaul of the ZRX token, adding extra functionality, allowing ZRX holders to delegate their stake to a market maker to earn passive rewards while retaining their voting capacity.
0x was founded in 2016 by Will Warren and Amir Bandeali. The two co-founders continue to serve the platform, with Will Warren as 0x's CEO, whereas Amir Bandeali is CTO.
The platform launched following a successful initial coin offering (ICO) in 2017, during which it raised a total of $24 million — with support from prominent investment firms including Polychain Capital, Pantera Capital and FBG Capital.
Prior to the sell-out ICO, Warren worked in several research roles and briefly held the role of technical advisor to Basic Attention Token (BAT). Bandeali, on the other hand, graduated from the University of Illinois with a BSc in Finance and held several trading positions before co-founding 0x.
Now the team is composed of more than 30 individuals, including engineers, researchers and designers who work to update the platform and keep it running smoothly.
Unlike many other Ethereum decentralized exchange protocols, 0x supports both fungible (ERC20) and non-fungible (ERC-723) tokens. This means it can be used for the permissionless trading of a wide range of assets, giving holders a way to buy, sell and exchange the vast majority of Ethereum assets through more than a dozen different apps.
The 0x protocol can be applied to a wide range of use cases, including eBay-style marketplaces for digital goods and services, OTC trading desks, exchange functionality for DeFi protocols and plain-old decentralized exchanges.
Although 0x can be used to build highly flexible exchange products, it can also be built into products where asset exchange is a secondary feature — such as for in-game purchases and portfolio management platforms.
On the 0x protocol, liquidity takers pay a fee in the form of ZRX tokens — this fee is used to incentivize market maker (relayer) liquidity. Users also need to pay a protocol fee in the form of Ether (ETH), which is used to pay for the gas used in any transactions they complete. As an open-source protocol, 0x does not receive any share of this revenue, and is instead supported by ZRX tokens unlocked as team and developer incentives — along with its initial ICO funding.
Like many digital assets, the ZRX token has a fixed maximum supply that will never be exceeded. This is set to 1 billion ZRX. Right now, around three quarters of this maximum supply is already in circulation, and just a small fraction of this is locked up for staking rewards.
Unlike many protocols, 0x has never publicly described the emission rate for new ZRX tokens, making it difficult to say how long it will take until the circulating supply is fully diluted. But with 50% of the circulating supply released when the token launched in August 2017 and 75% of the supply released as of October 2020, this indicates it may achieve full dilution in the early 2020s.
As per an early blog entry by 0x CEO Will Warren, half of the total ZRX token supply was sold to investors in the 2017 ICO, whereas 15% each is reserved for the 0x core development organization and external project development fund, while a further 10% is reserved for the founding team with a four year vesting schedule and one year cliff, and the remaining 10% is retained for early backers and advisors.
0x is built on top of the Ethereum blockchain. As a result, it is protected against attacks by the combined efforts of the massive Ethereum miner and node network.
As for the underlying smart contracts, version 3 of the protocol has been audited by several third party firms which checked to see if there were any underlying vulnerabilities, backdoors and redundant functions, including ConsenSys Diligence — no major issues were found.
However, a vulnerability was found in the v2.0 smart contract, which was later patched by the 0x core team. This vulnerability was detected by an independent researcher and was not exploited. 0x continues to operate a generous bug bounty, to help detect and patch any issues before they can be exploited.