IOTX is the native coin of the IoTeX layer-1 blockchain. IoTeX's documentation says its role is "similar to Ether (ETH) in Ethereum." IOTX pays transaction fees, rewards the nodes that propose blocks, is staked by validators as collateral, and is staked by holders to vote for delegates. The documentation lists a maximum supply of 10 billion IOTX and a total supply of 9,441,378,959 IOTX, and says "All IOTX are in circulation." The largest recent change is the Zanzibar hard fork, scheduled for 19 October 2026, which moves voter staking rewards into the protocol.
What changed in 2026
October 2026: staking rewards move on-chain (Zanzibar)
IoTeX's node software release v2.5.0 (published 28 September 2026) carries the Zanzibar hard fork. The iotex-core release notes set its activation at mainnet block 53,533,081, with an estimated time of 19 October 2026, 02:00 UTC. The notes recommend that node operators upgrade directly to v2.5.1, a maintenance release published 4 October 2026.
Zanzibar implements IIP-59, which was proposed on IoTeX's community forum on 31 July 2026. Until now, an off-chain service called Hermes paid out voter rewards. Under IIP-59 the chain does this itself: it splits each delegate's reward and pays voters directly. The proposal describes the change this way:
- Payouts are batched once per reward era, "currently 24 epochs (roughly a day)."
- Voters do not send a claim transaction and pay no distribution fee.
- Voters who used Hermes "ForwardRegistration" must re-register. Existing "AutoDeposit" registrations carry over.
According to TokenPost's 19 October 2026 report, the first payout under the new system was scheduled for 20 October, and Zanzibar also adds BLS proof-of-possession checks ahead of IIP-52 signature aggregation.
October 2026: a 1:1 portal for old Ethereum IOTX
Before the IoTeX mainnet launched, IOTX was issued as an ERC-20 token on Ethereum. IoTeX's token-formats page calls this version IOTX-E, at contract 0x6fB3e0A217407EFFf7Ca062D46c26E5d60a14d69. ChainCatcher reported on 13 October 2026 that IoTeX launched an "IOTX Redemption Portal" that swaps this ERC-20 IOTX for native IOTX at 1:1 with zero fees, citing an X post from IoTeX's account. Confirm the portal's address and terms on IoTeX's own channels before sending tokens.
June 2026: Pectra-era EVM upgrade
The v2.4.0 release (published 7 May 2026, labelled "mandatory") contains the Yap hard fork, with an estimated activation of 7 June 2026. It adds EIP-7702, which lets an ordinary account temporarily delegate execution to a smart contract. It also adds a candidate exit queue for delegates.
February 2026: the ioTube bridge exploit
On 21 February 2026 an attacker exploited the Ethereum side of ioTube, IoTeX's cross-chain bridge. In its 28 March 2026 review, IoTeX gave this account:
- An employee's machine was compromised, likely through social engineering, and a validator contract was upgraded to a malicious version.
- About $4.4M in bridge reserves was drained, and 410M CIOTX, the cross-chain form of IOTX, was minted.
- "The IoTeX L1 chain itself was never compromised," and "the total supply and circulating supply of IOTX was never affected."
- The chain was paused and came back online on 24 February. Mainnet v2.3.4 froze about 45M IOTX in attacker wallets, and CIOTX was deprecated under IIP-56.
- Affected users with losses of $10,000 or less are repaid in full in stablecoins. Users with larger losses get $10,000 at once and the rest in quarterly payments over 12 months, funded from the Foundation Treasury.
What IOTX is used for
The IOTX token page in IoTeX's documentation lists these uses:
- Fees. "Anyone initiating a transaction must pay a fee in IOTX." The fee pays the nodes that validate, execute and record the transaction.
- Block rewards. "IOTX is used to reward nodes who successfully propose new blocks."
- Validator collateral. "Validator nodes stake IOTX as a form of commitment and collateral."
- Delegate votes. Token holders stake IOTX "to vote for delegates."
- Burn-Drop. When a new IoT device is registered on the chain, a set number of IOTX is burned, and a matching amount is airdropped to stakers.
The same page warns that "the IOTX utility and tokenomics are being updated in IoTeX 2.0," so the Burn-Drop description is the documented design and may change.
IoTeX's 2.0 overview from 18 July 2024 adds a further use. Providers of DePIN infrastructure modules (such as W3bstream, ioID and ioDDK) stake IOTX to join a Modular Security Pool. The overview says "IOTX will be the foundational currency of the DePIN sector." That is the project's stated aim, not a measured outcome.
What each IoTeX source says IOTX does
How does IoTeX's 2020 tokenomics post compare with its current documentation, job by job?
Each cell reports what that source says, not whether the job is running today, and the documentation notes the token model is being updated in IoTeX 2.0.
How staking and delegate elections work
IoTeX's consensus is called Roll-DPoS. The consensus page describes it like this:
- Holders stake IOTX and vote for delegates. The candidate pool has "at least 36 delegates."
- For each round, a random committee of 24 is drawn from the pool using a verifiable random function (VRF).
- Candidates stay fixed for one epoch of 30 rounds. A block is produced "roughly every 2.5 seconds."
- A block is final once more than two-thirds of the committee agree that it is valid.
Votes therefore decide which delegates can be drawn to produce blocks and earn block rewards. Voters receive a share of those rewards according to each delegate's settings. Since Zanzibar, the protocol pays that share directly, as described above. IoTeX's 2020 post, Tokenomics Part 1 (11 June 2020), described the older version of the same design: "24 of the top 36 voted Delegates are randomly selected to produce blocks every hour."
How much IOTX exists, and why sources disagree
| Figure | Value | Source and date |
|---|---|---|
| Maximum supply | 10 billion IOTX | IoTeX docs, undated |
| Total supply | 9,441,378,959 IOTX | IoTeX docs, undated |
| Created at mainnet launch | 10 billion IOTX in 2019 | CoinMarketCap, About section |
| Circulating supply | about 9.6 billion IOTX | CoinMarketCap, "as of August 2025" |
| Circulating supply | 9.44B IOTX | CoinMarketCap statistics table, undated |
| Staked | over 3.6 billion IOTX, "about 38% of supply" | CoinMarketCap, undated |
| Staked share | 20% | iotex.io/iotx, undated |
The figures do not line up. CoinMarketCap gives 9.6 billion and 9.44 billion for circulating supply on the same page, and the 38% and 20% staked shares come from different, undated pages. None of these sources explains the gap between the 10 billion created at launch and the 9.44 billion total. If you quote an IOTX supply or staking figure, name its source and date.
Which IOTX you hold
According to IoTeX's token-formats page, IOTX exists in several forms:
- Native IOTX on the IoTeX L1. Only this form pays fees and can be staked natively.
- IOTX-E, the original ERC-20 on Ethereum, which the October 2026 portal is meant to convert.
- WIOTX, an ERC-20 wrapper on IoTeX, swappable 1:1 with native IOTX.
- CIOTX, the cross-chain variant used by bridges. IoTeX deprecated it after the February 2026 exploit.
Check the contract address against IoTeX's documentation before you move or swap tokens.
