Bancor AMM Design: Single-Sided Liquidity and Impermanent Loss Cover
Summary
This article explains Bancor’s automated market maker design and the role of BNT as a connector asset across token pools. It focuses on changes introduced in Bancor v2.1 to reduce barriers for liquidity providers: single-sided deposits and impermanent loss (IL) compensation. The protocol can mint BNT to match a token deposit, then burn or replace that BNT as liquidity changes. Swap fees from protocol-owned liquidity may fund IL payouts, with new BNT described as a backstop if reserves are insufficient.
The article gives historical examples and protocol figures to support its claims, including compensation relative to fee revenue and a modeled estimate of potential supply expansion if all liquidity were withdrawn. It also describes progressive coverage, a minimum participation period, and a lockup, alongside governance whitelisting and the higher insurance costs associated with stablecoin pools. These figures and claims refer to the protocol’s state around 2020–2021; the article is not evidence that coverage remains sustainable or that LP positions are risk-free.
Key ideas
- Bancor routes token trades through BNT, which serves as a connector across liquidity pools.
- Protocol-minted BNT can enable single-sided deposits without requiring LPs to supply a matching asset upfront.
- Impermanent loss compensation is paid on withdrawal and is funded first from protocol fee revenue, with minting as a possible backstop.
- Coverage accrues over time and is subject to minimum periods and governance approval.
- The design’s limits include potential BNT dilution, restricted token eligibility, and higher insurance costs in stablecoin pools.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.