According to BlockBeats news on July 30, monitored by EmberCN, a giant whale that had been dormant for over 14 years holding 3,963 BTC woke up a few days ago and gradually sold off through market makers:
This address transferred out 450 BTC (approximately 53.42 million USD) after ending its dormancy, of which 150 BTC entered Coinbase and affiliated addresses of market makers B2C2 and Wintermute in batches over the last 5 days. The address still holds 3,678 BTC (approximately 434 million USD).