Decentralized finance (DeFi) is a rapidly evolving blockchain technology that offers a new perspective on financial services through web3 applications. DeFi offers developers the flexibility to create financial services using smart contracts, leading to a lack of standardized protocols and challenges in applying traditional finance models for risk assessment, especially during the early stages of adoption. The Maker protocol is a prominent DeFi platform known for its diverse functionalities, including loan services. This study focuses on analyzing the risk associated with Maker’s loan portfolio by developing a risk model based on multiple Brownian motions passage levels with Brownian motions representing different collateral types and levels being users’ collateralization ratios. Through numerical experiments using artificial and real data, we evaluate the model’s effectiveness in assessing risk within the loan portfolio. While our findings demonstrate the model’s potential for assessing risk within a single DeFi project, it is important to acknowledge that the model’s assumptions may not be fully applicable to real-world data. This research underscores the importance of developing project-specific risk assessment models for individual DeFi projects and encourages further exploration of other DeFi protocols.