Investors can use on-chain data to assess a project's credibility by analyzing transaction history, wallet activity, and token distribution. Key metrics like wallet balances, token flows, and the number of active addresses can indicate the project's transparency and liquidity. Examining the project's smart contract code and audit reports ensures security and reduces the risk of vulnerabilities. On-chain data also helps investors track the project's governance, developer activity, and partnerships, providing insights into its growth and sustainability. Additionally, assessing token supply and staking behavior can show investor confidence and long-term commitment.