Balancing Act

Building on top of a gnarly bug in some dex math, an attacker constructs a flashswap strategy that leaves a crypto protocol’s liquidity pools drained of over a hundred million dollars. Wait wait wait, haven’t we seen this before? Don’t worry, this isn’t Cetus Part 4. Instead, we’re talking about the November 2025 hack of Balancer.  You see, when Balancer was doing its math on your transaction, there was one small step that would always round a number down. A small thing maybe, but when you’re a galaxy brain hacker with all the tools of defi at your disposal, you’ll find a way to lever that up into millions of dollars. Let’s find out how.