1,581 Bitcoins (BTC), worth approximately $100 million, were transferred from an anonymous address to a Coinbase address on [Date]. The transaction was flagged by Whale Alert, a popular blockchain tracking service. It is unclear who initiated the transfer or the reason behind it. Coinbase is a well-known cryptocurrency exchange and wallet service. The transfer of such a large amount of BTC to Coinbase could indicate that the sender is planning to sell the coins or use them for other purposes.