The opening of the US stock market (Beijing time 21:30) is a high liquidity period, and its sentiment and capital flow will quickly transmit to the Bitcoin market. This linkage mainly stems from the overlap of investor groups in both markets, namely institutional investors. When the US stock market opens with a big rise or big fall, it directly affects the risk preferences and capital allocation decisions of this group of investors, leading to synchronous and severe fluctuations in the Bitcoin market.

For traders, understanding the significance of this correlation lies in risk management. The opening hours of the U.S. stock market are known to be a high volatility window, during which market liquidity, volatility, and liquidation risks significantly increase. Seasoned practitioners will adjust their positions accordingly, set wider stop-losses, or avoid high-leverage operations at this time to cope with the potential for severe fluctuations in both directions.