mikemcdonald
commented
4 years ago Won't fix - any token upgrade mechanism greatly increases centralization and control of contracts. Adds additional complexity. Added to docs at - https://docs.balancer.finance/-LtRAKuhb1ZIm1X-H-IS/protocol/limitations
Severity: High Difficulty: High
Description
Once the pool is finalized, no token can be added or removed. If a token is migrated to a new address, the pool will not follow this migration.
In this situation, the pool's value will not stay stable, and all the liquidators are likely to withdraw their deposits as soon as possible, leading the slowest liquidators to lose their deposits.
Recommendation
Adding a mechanism to handle token's migration will increase significantly the code complexity, and potentially remove the trust in the system.
Balancer should study what solutions could be implemented, and properly document what happens in the case of migration. If no on-chain mechanism is present to follow a token's migration, the documentation should highlight off-chain strategies. For example, if the pool's value is significant, it might be possible to contact the token's owner to ask for a migration to a new pool (if all the assets can be migrated).