A smart contract is a program stored on a blockchain that automatically executes predefined actions when specific conditions are met. Once deployed, the code runs exactly as written, without requiring a trusted intermediary. Smart contracts are the foundation of decentralized applications (dApps), DeFi protocols, NFT marketplaces, and DAOs.
A developer writes the contract logic in a language like Solidity (for Ethereum) or Rust (for Solana), compiles it, and deploys it to the blockchain as a transaction. Once on-chain, the contract has its own address and can hold funds, interact with other contracts, and execute logic when called. The blockchain's consensus mechanism guarantees that every node runs the same code and agrees on the output.
For example, an escrow smart contract might hold a buyer's payment and release it to the seller only when a delivery confirmation is recorded. No bank, lawyer, or payment processor is needed. The code enforces the agreement automatically, transparently, and irreversibly.
Smart contracts remove the need to trust individual parties in a transaction. The code is public, auditable, and executes identically for everyone. This has enabled entirely new categories of applications: automated market makers that provide liquidity without order books, lending protocols that algorithmically set interest rates, and governance systems where token holders vote on proposals that execute automatically. The entire DeFi ecosystem runs on smart contracts.
The Prediction Markets panel shows data from Polymarket, which uses smart contracts to manage bets on real-world events. The Crypto Movers panel tracks tokens that are themselves smart contracts on various chains. Gas fees shown in crypto panels are the cost of executing smart contract operations.