There have been numerous allegations that Elon Musk sold bitcoin to prove liquidity, and this led to the sale of 10% of Tesla's assets.
But Elon Musk denied the claim, saying that he had not sold any of his bitcoins, and that Tesla had sold some of its bitcoins in the first three months of the year & earning $ 272 million.
The news shows that Elon Musk and Tesla have chosen a large amount of bitcoin as their capital, and by accepting bitcoin for their own transactions, they are launching a bitcoin revolution.
Source:
https://cointelegraph.com/news/i-have-not-sold-any-of-my-bitcoin-elon-muskIt seems that Elon musk holding some BTC for his personal asserts too and his company Tesla also invested in BTC.
These two things are different. If Bill Gates buy BTC, we won't say Microsoft has bought BTC. It is his personal investment not investment by his company.
But yes Elon musk did use his position and popularity to manipulate the market price. Dige coin is classic example how people are influenced by celebrities in their buying decisions.