According to Reuters, based on Friday’s figures, Bitcoin is down nearly 15 percent this week at $49,804.
Dogecoin is down about a third since last Friday, tumbling after Musk referred to it as a “hustle” during his appearance on US TV programme, Saturday Night Live.
But the cryptocurrency then jumped 20 percent after Mr Musk’s latest comments that he was involved in work to improve its efficiency.
Mr Musk tweeted: “Working with Doge devs to improve system transaction efficiency. Potentially promising.”