Arbitrum

Arbitrum is the largest optimistic rollup by TVL and transaction volume.按总锁仓量（TVL）和交易量计算，Arbitrum 是最大的乐观 Rollup（Optimistic Rollup）。

Arbitrum's Nitro upgrade reduced costs dramatically, cementing its position as the top Ethereum L2 by user activity.Arbitrum 的 Nitro 升级大幅降低了成本，巩固了其作为按用户活动量计算的顶级以太坊 L2 的地位。