The Protocol: Robinhood unveils its layer-2 testnet

Also: Citadel Securities backs LayerZero chain, MegaETH mainnet debut and ENS scraps L2 plans

What to know:

Welcome to The Protocol, CoinDesk's weekly wrap of the most important stories in cryptocurrency tech development. I’m Margaux Nijkerk, a reporter at CoinDesk.

In this issue:

Robinhood starts testing its own blockchain as its push into crypto and tokenization deepens.

Citadel Securities backs LayerZero as it unveils ‘Zero’ blockchain for global markets.

MegaETH debuts mainnet as Ethereum scaling debate heats up.

Ethereum's ENS identity system scraps planned rollup after Vitalik's warning about layer-2 networks.