Bitcoin's Volatility Clock Ties to Wall Street Hours

A recent study analyzed data from Kraken's XBT/USD market between 2016 and 2025, finding that Bitcoin's price discovery has become increasingly concentrated in the US hours. The study found that the nine hours from 13:00 to 21:59 UTC accounted for 50.6% of Bitcoin's daily realized variance between 2022 and 2025, up from 38.4% in 2016-2018.

This shift suggests that Bitcoin's volatility has become tied to the US equity calendar, particularly during American business hours. The study found that the most volatile hour for Bitcoin moved with the shift in the American trading session, and that the variance-weighted center of the US window also moved 0.33 hours later.

The study tested this pattern by analyzing the impact of US daylight-saving transitions and NYSE holidays on Bitcoin's volatility. During 2022-2025, Bitcoin's share of variance occurring during US hours fell by 13.9 percentage points on weekday US market holidays compared to matched trading days.

The trend extends beyond Bitcoin, with similar increases in the US-hours share of variance appearing in six of seven other long-listed crypto assets tested on Kraken, including Ethereum, XRP, Solana, Cardano, Dogecoin and Chainlink. The study suggests that institutionalization is a broader explanation for this shift, rather than assigning it to one product.

The findings have implications for trading firms, as risk models that assume volatility is distributed relatively evenly across the day can understate exposure during the US session and overstate it overnight.