Blast is an L2 based on Optimism that modifies the native ether token to be rebasing. Blast also provides a rebasing ERC-20 stablecoin called USDB. Blast users and smart contracts can earn ~4% from beacon chain staking yield and ~5% from US treasury bill yield, and those yields are reflected in their accounts automatically without them sending any transactions. Additionally, Blast also redirects sequencer fees to the dapps that induced them, allowing smart contract developers to have an additional source of revenue.

Blast features

Rebasing ETH balances on the L2

Sequencer fees to dapps


High level implementation overview

This overview will assume a working understanding of OP stack based L2s and focus on Blast’s unique changes.

Depositing ETH

When ETH is bridged from the L1, it ultimately ends up in the Blast YieldManager contract. This contract is responsible for staking the ETH in yield bearing protocols like Lido. On the L2, ETH is represented in terms of shares, such that the global share price multiplied by the number of shares equals the ETH value that was bridged over. The account node corresponding to the recipient of this ETH stores the number of shares and not the number of wei.