Exploring PSBT in Bitcoin DeFi: Security Best Practices

**Executive Summary:** CertiK examines Partially Signed Bitcoin Transactions (PSBT), their role in modern Bitcoin applications (Ordinals, marketplaces, DeFi), and common implementation pitfalls—highlighting misuse of SIGHASH flags (with a real Atomicals Market theft example), poor UTXO selection, and accidental burning of ordinal assets—then offers a detailed PSBT security checklist and mitigation recommendations.