According to on-chain analyst @ai_9684xtpa, Binance seems to be silently doing the work of a large cross-chain bridge for users. In the face of L2 > L1 cross-chain requirements, in addition to official cross-chain bridges and third-party cross-chain aggregators, it is also a common choice to complete cross-chain directly through exchanges, without a 7-day waiting period, and the handling fee is relatively considerable. Perhaps in response to the situation of "a large number of Arb ETH deposits to Binance but mainnet ETH", it is suspected that Binance address 0xE69... e3Abb has initiated a withdrawal application for 190,000 ETH (worth 513 million US dollars) in Arbitrum in the past week; the earliest withdrawal of 20,000 ETH has passed the waiting period and been recharged back to Binance Hot Wallet. It is currently seeking verification from Binance on this information.