You can see we made small increases to the rake recently, but you can also see the value of Bitcoin has fallen since 3.0 launched.
Bitcoin fluctation price should not affect to rake. Rake is paid based on a % of the pot so the price of bitcoin in $ have no relation.
If a player plays for example in limit 10/20 and bitcoin price falls to half then the same player can play in limit 20/40. Rake should not affect this.