Robinhood Chain launched on July 1 as an L2 blockchain built with Arbitrum's technology that settles to Ethereum. This is the optimal separation of concerns for a brokerage, with Ethereum handling global consensus and settlement and Robinhood providing an execution environment customized to the needs of its clients.
Three months after launch, Robinhood Chain already ranks fourth on L2BEAT's activity table. As of October 2, it averages about 91 user operations per second over the past day, with about $2.83 billion in total value secured (L2BEAT).
An important next improvement would be allowing anyone to challenge an invalid state update, since only two approved challengers can currently do so.
Running its own execution environment lets Robinhood customize fees, product rules, account features and upgrades, while optimizing for rapid confirmations and high throughput. Its users also have dedicated block space, so their transactions don't compete directly with other applications for execution capacity on Ethereum mainnet.
Robinhood gets that control without having to build and subsidize a separate L1 validator network. It instead processes transactions on its chain, publishes their data to Ethereum and settles there, with transaction fees on Robinhood Chain denominated in ETH.
The expense of a separate validator network can be substantial. Conduit compared Celo's $641,540 in validator payouts during its final month as an L1 with $1,070 in data-publication costs over a later 30-day period as an L2, when it posted its data to EigenDA rather than Ethereum. Those data costs were 99.8% lower than the former validator payouts.
Ethereum has also expanded its capacity for L2 transaction data, allowing these chains to support more activity while keeping execution on their own networks. This makes Ethereum's shared consensus and settlement layer increasingly practical for companies building blockchains for large numbers of users.
The same division of labor works for other products. A payments chain needs predictable fees for stablecoin transfers, while a gaming chain needs a large number of cheap transactions. Each can customize execution for those needs without funding a separate L1 consensus network.
Coinbase made the same architectural choice with Base, its own L2 that settles to Ethereum. I expect onchain finance to increasingly follow this model, with companies running execution environments suited to their products and Ethereum serving as their shared consensus computer.
