In a significant market movement, Bitcoin surged past $63,000 on Thursday, pulling the altcoin market along in its wake. However, this rally was somewhat tempered by a negative outflow day for US Bitcoin Exchange-Traded Funds (ETFs), as well as those in Hong Kong. This development has raised questions about the sustainability of Bitcoin's current rally. The market is now closely watching to see if Bitcoin can maintain its upward trajectory in the face of these outflows.