Pools house mStable's liquidity pools (Feeder Pools) which provide efficient mAsset on/off ramps, generate additional swap volume, leverage mAsset’s Save utilisation rate.

Feeder Pools

Feeder Pools (fPools) provide efficient mAsset on/off ramps, generate additional swap volume, leverage mAsset’s Save utilisation rate, and enable mStable to add any number of pegged asset to the protocol.

What are Feeder Pools?

fPools introduce a new invariant for 2-asset stablecoin AMMs that shows similar properties as Stableswap, but can be solved with a lower number of operations, i.e. they are more efficient.

fPools are composed of 50% fAsset (e.g. BUSD, GUSD) and 50% mAsset (e.g. mUSD).

Why introduce Feeder Pools?

Feeder Pools (fPools) provide important benefits to mAssets by:

  • Freeing fAsset -> mAsset swaps (effectively allowing users to ‘mint’ mAssets with any fAsset)

  • Leveraging the mAsset SAVE rate by providing a source of demand for mAssets from within mStable (thus increasing mAsset SAVE APY)

  • Feed swap fees back into the mAsset by supporting trades between fAsset <-> mAsset bAssets

How do Feeder Pools and mAssets differ from each other?

fPools maintain the bulk of functionality from mAssets:

  • Same interface for Mint/Swap/Redeem

  • Ability to deploy fAsset/mAsset onto third party lending platforms to generate yield

  • Ability for Meta Governors to enable a governance fee, which extracts a % of total pool revenue

  • Governed by vMTA holders

However, there are a number of core differences between fPools and mAsset pools:

  • fPools produce LP tokens that increase in value, rather than inflate in supply, creating a new universe of composable yield tokens generated by mStable

  • Swaps into mAssets do not apply a fee, making fPools the most efficient place to trade mAssets

  • fPools are always composed of 50/50 fAsset/mAsset, and use an invariant derived optimised for trading 2 assets

  • fPools will soon be permissionless, i.e. anyone will be able to create them.

  • fPools are separate contracts from the mAsset pool and so do not impact the risk profile of mAssets. This means that any pegged asset can be added without impacting the integrity of mAssets.

What Feeder Pools are currently available?

There are 5 feeder pools currently live:



What do I earn for providing liquidity into Feeder Pools?

By contributing liquidity to an fPool, the liquidity provider will receive:

  • Swap fees into the bAsset specific to that fPool

  • MTA rewards that vest over time (if deposited into the Vault)

Feeder pools on mStable have low impermanent loss risk.

How are rewards from the Feeder Pools given?

  • Rewards are given in MTA

  • 1/3 of MTA rewards are claimable immediately

  • 2/3 of MTA rewards are streamed linearly after 26 weeks

Why is there a range of APYs for Pools?

  • Rewards from providing liquidity can be boosted by staking MTA

  • Liquidity providers can achieve a maximum boost of up to 3X depending on their amount deposited and staked MTA (vMTA), i.e. voting power

What is the difference between the Vault and Pool?

  • MTA rewards go to users who provide liquidity to Feeder Pools

  • When providing liquidity, liquidity providers receive LP tokens that represent their share in the liquidity pool

  • The Vault is used to meaure who is providing liquidity and distribute MTA through a smart contract

  • To qualify for MTA rewards, the LP tokens must be staked in the Vault

Where can I find the old Earn Pools?

  • If you have previously deposited into the old Earn Pools, you can find them here

  • These pools include

    • MTA/WETH Uniswap Pool

    • mUSD/3Pool Curve Pool

    • MTA/mUSD 95/5 Balancer Pool

    • MTA/mUSD 80/20 Balancer Pool

    • USDC/mUSD 50/50 Balancer Pool

    • MTA/mUSD 5/95 Balancer Pool

    • WETH/mUSD 50/50 Balancer Pool