MonoX
HackedDeFi · born 2021 · ✝ 2021
Sold a token to itself to pump its own price.
MonoX was a single-token AMM protocol on Ethereum and Polygon that let liquidity providers pool one asset at a time. In 2021 an attacker abused its swap pricing to inflate a token's value and drain roughly $31.4M.
- Peak
- ~$31.4M stolen
- Cause
- Hacked
- Year of death
- 2021
☠️ Cause of death
The swap function failed to block trading a token for itself, letting the attacker repeatedly self-swap to ratchet up its price and then cash out the protocol's other assets.
📓 Lessons left behind
- —Block self-swaps and degenerate trading paths explicitly.
- —Pricing that updates mid-transaction invites manipulation.
- —Novel AMM designs multiply the surface for pricing bugs.
🌱 The idea that survived
Sanity-checked swap pricing
Drove AMMs to validate trade inputs and guard against same-token and self-referential price updates.
#defi#amm#price-manipulation#ethereum