A Bitcoin whale has added $200 million worth of Bitcoin to its stash, bringing its total holding to over 15,000 Bitcoin.The whale had sold over 11,400 Bitcoin in the past few months but recently started acquiring again.In a separate incident, another Bitcoin whale woke up after eight years and moved over 3,000 Bitcoin, worth $250 million.BlackRock, the world's largest asset manager, has also been accumulating more Bitcoin in recent weeks.