This can have a big impact on the market and if they sell all of them we can see a crash on the crypto market. But it can also happen that all of these are just manipulation to create panic on the market and crash it. Then they will make profit from buying in dip.
The fact is that in most cases, information about such transactions is used by third parties in their favor, creating a panic mood in the cryptocurrency market, in order to profitably buy at low prices an asset is in high demand. But in fact, such amounts of funds are transferred not for sale, but for further use in business. As recently, there was a transaction for more than $ 1 billion in Ethereum, but the transfer took place on a smart contract of the protocol for lending and earning from investments.