Bitcoin was holding around $38,500 -- having almost fallen through $30,000 recently for the first time since January -- after Musk tweeted support for a group attempting to make the mining of the currency less environmentally damaging.
China, which powers nearly 80 percent of the global cryptocurrency trade, relies on a particularly polluting type of coal, lignite, to power some of its mining.
"It's no surprise to me, as Chinese capital controls can be challenged by cryptocurrency purchases in the country and transfers out of the country," Adam Reynolds, of Saxo Markets, said.
For an asset class that has surged this year, with dogecoin up about a hundredfold, ether up more than fourfold and bitcoin gaining 45%, some are beginning to call time on the wild ride.
Ecoark intends to convert it into dollars, but Lohstroh plans to hold the bitcoin he mines, which he believes will one day underpin a new global financial system.
Subscriptions to the software for the system would be offered within a month, Musk said in a Twitter exchange without elaborating further.
Tesla has released what it describes as a beta version of its full self-driving program to a limited number of employees and customers since October. Musk has touted the capability on Twitter.
Asperger Syndrome is a neurodevelopmental disorder that manifests itself with difficulties in engaging in social interactions and nonverbal communication.
Elon Musk is being lauded for openly admitting to being on the spectrum.
The planned lunar version of Starship would however serve a more modest goal -- docking with a future lunar orbital station, collecting astronauts, then setting them down on the Moon.