Definition. The net USD value flowing into or out of Ethereum bridge smart contracts, computed as bridge deposits minus bridge withdrawals. Equivalently, the net USD value moving in or out of the Ethereum blockchain via bridges.

Technical. Only bridge contracts on the Ethereum side are included. Coverage spans bridge deposits into both L1 and L2 destinations, capturing value transferred to L1 competitors and to L2 scaling solutions. Each bridge represents a single destination chain, except those labeled multichain, which transfer assets across several chains. Bridges are protocols that move digital assets between blockchains: when an asset leaves Ethereum it is deposited and locked into a bridge contract, and when it returns it is withdrawn and released.

Interpretation. Positive values mean more value is being deposited into bridges, i.e. a net outflow from Ethereum. Negative values mean more value is being withdrawn from bridges, i.e. a net inflow back to Ethereum.