---
id: 1326
title: "Balancer hack analysis and guidance for the DeFi ecosystem"
source_domain: blog.trailofbits.com
source_url: "https://blog.trailofbits.com/2025/11/07/balancer-hack-analysis-and-guidance-for-the-defi-ecosystem/"
published_at: "2025-11-07 23:00"
tags: ["web3", "smart-contracts", "defi", "fuzzing", "blockchain", "exploit-analysis", "rounding-vulnerability", "invariant-testing"]
phying_url: "https://phying.com/item/1326"
lang: en
---

# Balancer hack analysis and guidance for the DeFi ecosystem

## Summary

A retrospective on the $100M Balancer v2 hack, caused by a long-dormant rounding direction flaw, with guidance on invariant testing, fuzzing, and formal verification for DeFi teams.

## Intelligence Metadata

- **Sources:** blog.trailofbits.com
- **Published:** 2025-11-07 23:00
- **Original:** https://blog.trailofbits.com/2025/11/07/balancer-hack-analysis-and-guidance-for-the-defi-ecosystem/
- **Phying News:** https://phying.com/item/1326