Vetr Lunde, head of research at crypto research firm K33 Research, has published a comprehensive analysis examining the long-debated claim that there is a systematic sell-off at 10am in the Bitcoin market.
Lunde’s research, which examined more than 606,000 minutes of data from January 1, 2025 to February 26, 2026, found that Bitcoin’s average return as of 10 a.m. ET is in the top quartile of strongest intraday time frames.
According to the analysis, Bitcoin’s average minute-to-minute return during the period was approximately -0.003 basis points, while the average return at 10:00 was calculated to be 0.207 basis points. This performance makes 10:00 the 359th strongest hour of the day. In other words, 75% of the time during the study period, performance was worse than at 10:00. Lunde argued that this data does not support the general theory that systematic price declines occur at 10 o’clock.
The 10am systematic decline theory is based on the claim that Bitcoin regularly declines, particularly around 10am ET, which could be related to market maker and ETF flows. However, Lunde noted that extensive datasets “quickly refute” this view.
Meanwhile, the analysis revealed that over a narrower period (November 1, 2025 to February 26, 2026), the average return as of 10:00 dropped to -1.41 basis points. During this period, 10:00 was the 35th worst time of the day and within the weakest range of 2.36%. In 53.85% of the days studied, negative returns were observed at the 10:00 minute, and in 12% of the minutes, the frequency of negative returns was higher than at 10:00. Lunde acknowledged that 10 o’clock could appear as a “negative outlier” in short-term samples, but said this was not enough to directly indicate market manipulation.
Additionally, if you examine the time frame around 10:00, the image appears to be more balanced. The average return was -0.0033% between 09:55 and 10:05, +0.0017% between 09:50 and 10:10, and +0.0038% between 10:00 and 10:10. Losses remained fairly limited in the wide 9:30-10:30 and 10:00-11:00 hours.
Runde also pointed out that it is not possible to assess the weakest period by focusing solely on “round time.” From November 1, 2025 to February 26, 2026, the worst-performing times included “irregular” times such as 10:12, 09:41, 17:13, 10:46, and 14:02. He argued that this was indicative of general volatility dynamics associated with US trading hours, rather than a specific time-focused operation.
One of the clearest results of the analysis is that Bitcoin volatility increases significantly when the US market is open. Volatility is especially intense in the minutes leading up to the release of US macroeconomic data and the opening of the stock market. The period immediately following the opening of the US stock market from 09:31 to 09:37 (ET) represents peak volatility. This shows that the microstructure of the Bitcoin market is closely related to the US stock market.
In conclusion, Lunde said the data does not provide clear evidence of intentional and systematic selling at any particular time.
*This is not investment advice.
