Pool Lifecycle

Any user can create a new pool by calling newBPool() on the BFactory contract. The caller is set as the controller or pool owner.

Pools can exist in one of two states: controlled or finalized. Pools start in a controlled state and the controller may choose to make the pool finalized by calling finalize(). Finalize is a one-way transition. While in a controlled state, outside actors cannot add liquidity. A controlled state allows the controller to set the pool's tokens and weights.

BPTs

All pools in Balancer are also ERC20 tokens known as BPTs (Balancer Pool Tokens), which represent proportional ownership in the pool's liquidity. When users add liquidity through joinPool or joinswap* they receive BPTs proportional to the amount of assets they are adding to the pool.

Notes

BPTs are an opinionated ERC20 token implementation, and have a few subtle differences. transferFrom from itself does not require a previous allowance.