From Marketwatch:

"Musk felt compelled to respond in a late-Monday tweet to an earlier blog post that said a onetime employee at Musk’s Mars-focused SpaceX has made the bitcoin claim about his former boss. Satoshi Nakamoto is the nickname used by the unknown person or people who created bitcoin’s original reference implementation and devised the first blockchain database. The blog post made note of Musk’s knowledge of C++ and compared Musk to U.S. inventor and founding father Benjamin Franklin, who also published under a pseudonym.

Musk, the chief executive of Tesla Inc. TSLA, +0.68%  , also tweeted that he was gifted bitcoin once, but doesn’t know what he did with it."