In one sentence
Every chain is an independent ledger, and ledgers do not talk to each other by default. If you hold 100 USDT on Ethereum, Tron’s ledger has no idea.
But projects want to be wherever users are. So the same token often has a separate copy on several chains. What links those copies together, and who has the final say, is what you need to understand about any multichain project.
An intuitive example: USDT and USDC
Data as of 16 Oct 2026, 01:45 UK time · source DefiLlama
- Tron$93.03B
- Ethereum$73.06B
- BSC$9.18B
- Solana$2.84B
- Arbitrum$797M
- Plasma$738.4M
- Polygon$718.4M
- TON$550.3M
Data as of 16 Oct 2026, 01:45 UK time · source DefiLlama
- Ethereum$44.66B
- Hyperliquid L1$7.01B
- Solana$6.97B
- Base$4.4B
- Arbitrum$2.31B
- Polygon$1.64B
- BSC$1.59B
- Arc$614.6M
Data as of 16 Oct 2026, 01:45 UK time · source DefiLlama
USDT on Tron, on Ethereum and on BNB Chain are three different contracts, all called USDT, and you cannot send one directly to another. When an exchange asks you to choose a “withdrawal network”, you are choosing which chain’s copy you want.
How a token “crosses” over
Strictly speaking, a token never actually “travels” from one chain to another. What is called bridging is one of three methods:
- Lock and mint: lock the token in the bridge’s contract on chain A, and the bridge mints the same amount of a “wrapped token” on chain B. Later, burning the wrapped token on B unlocks the original on A. Whether the token on chain B is worth anything depends entirely on whether the tokens in that contract on chain A are still there.
- Burn and mint (native issuance): the issuer has its own contract on every chain; whatever is burned on A is minted on B, so total supply stays the same. USDC’s CCTP and the OFT / NTT standards used by many projects work this way. The risk concentrates in who holds the minting rights.
- Liquidity pools: the bridge keeps a pool of the token on both chains; you deposit on A and the bridge pays you from its pool on B. Fast, but a pool can be drained.
- 01Locked on chain A
You send the tokens into the bridge's contract on chain A.
One block - 02Bridge confirms
The bridge's validators (or oracles, or a light client) confirm the lock on chain A can no longer be rolled back.
A few minutes - 03Minted on chain B
The bridge mints the same amount of wrapped tokens for you on chain B.
- 04Used on chain B
The wrapped tokens can be traded, lent and borrowed on chain B.
- 05The return trip is the reverse
Wrapped tokens are burned on B and the bridge unlocks the originals on A.
Who performs the “bridge confirms” step, and how many signatures it takes to release funds, determines how safe the bridge is.
Why bridges get hit so often
Bridge contracts hold large amounts of real money, and the power to release it often sits with a handful of private keys. Several of the largest crypto thefts in history were bridges:
- Ronin bridge, March 2022: the private keys of 5 of its 9 validators were compromised and about $600 million was stolen (see Custom chains).
- Wormhole, February 2022: a signature-verification bug let the attacker mint about 120,000 wrapped ETH out of thin air, a loss of about $300 million.
- Nomad, August 2022: an upgrade introduced a bug that let anyone withdraw by copying someone else’s transaction; about $190 million was taken within hours.
- Multichain, July 2023: after the team behind a bridge literally called “Multichain” went silent, large amounts of the assets in the bridge were moved out, and the wrapped tokens it had issued lost their backing overnight.
Strengths and trade-offs
- Usable on whichever chain the user is on, with wider liquidity and reach.
- Native issuance (burn and mint) is now fairly mature, for example USDC's CCTP.
- Every extra chain adds another contract, another bridge and another set of signers to trust.
- Impostor tokens are everywhere: someone launches a token with the same name and logo on another chain, and it looks identical.
- Supply across all chains often fails to match the total the project publishes, and it is hard to spot at a glance.
- 01
Find the "contract address list" on the project's website or official docs and check it chain by chain. Treat any same-named token not on the list as fake.
- 02
How did the token on each chain come about: native issuance by the project, or a wrapped token minted by a third-party bridge? For wrapped tokens, check that bridge's security record.
- 03
Who holds the minting rights: how many multisig signers, and is there a timelock? Minting rights in a single wallet mean that party can print tokens at any time.
- 04
Add up the supply on every chain and compare it with the total the project publishes.
- 05
Check how deep liquidity is on each chain. If only one chain has a decent pool, prices on the others are easy to manipulate.
Data and sources
- Stablecoin distribution: DefiLlama stablecoin data (hover over a number to see its cut-off time).
- Bridge incidents are based on each project’s post-mortem and the Rekt leaderboard; amounts are US dollar values at the time.
- This guide is educational and is not investment advice.
Phishing sites often imitate these domains. Check the address bar before you visit.