What Is Bridge?
A bridge is a protocol that enables asset transfers between different blockchain networks. Since blockchains are isolated by design (Ethereum can't natively read Bitcoin's state), bridges serve as connectors — locking assets on the source chain and minting wrapped representations on the destination chain, or using liquidity pools to facilitate cross-chain swaps.
How Bridge Works
Bridges operate through various security models: trusted bridges rely on a set of validators or a multisig to attest to cross-chain transactions; light client bridges verify state proofs cryptographically; optimistic bridges assume validity unless challenged within a dispute period. Each model trades off between speed, cost, and security guarantees.
Why It Matters for Traders
Bridges are critical infrastructure for multi-chain DeFi but have historically been the most targeted attack vector in crypto — billions of dollars have been stolen from bridge exploits (Ronin, Wormhole, Nomad). When using bridges, prefer those with the strongest security models, longest track records, and deepest liquidity. Never bridge more capital than you can afford to lose through a single bridge.