Je ne sais pas. Peut-être ça:
https://www.kitco.com/news/2019-08-28/Is-bitcoin-about-to-tank-Self-declared-bitcoin-creator-ordered-to-pay-4bn-to-ex-partner.html

The upcoming CME futures expiration set for Friday is expected to have a significant effect on the next bitcoin price action as the biggest cryptocurrency threatens to plunge below the $10,000 mark.
[...]
According to a Tuesday post by the Skew Twitter account, the CME futures deadline will see almost 50% of open interest expire. According to past evidence, futures expiration sparks Bitcoin volatility. However, different events in Bitcoin’s history have behaved differently. Skew believes that the current investor appetites are more bearish.