While the blockchains themselves are secure, the applications running on the blockchain may not be. These applications interact with the blockchain through smart contracts, but just like any other software, bugs in the code can lead to security vulnerabilities. So to mitigate these risks, it is necessary to conduct security audits on the smart contract. Smart Contract Audit helps you find hidden exploits that might be present in the code. It would eventually reduce the risk and provide you an extra layer of security. Bug-free code is nice to have in other types of software, in blockchain applications, it is essential.