As the richest man on Earth, people will buy whatever that person says.
And Elon Musk who has a net worth shy of $200 billion, has instantly added $5,000 to Bitcoin's price, rising it to $37,299 at around 3:30 a.m., according to data from industry site CoinDesk.
At 5:17 a.m. ET, the popular digital coin was trading 16% higher at around $36,423.
What Musk did, was simply adding the hashtag #bitcoin to his Twitter bio.
He also sent out a cryptic tweet, saying: "In retrospect, it was inevitable."
This moment adds another volatility to the market.
Previously, the stock prices were heavily-shorted, with companies like GameStop had their stock prices surged dramatically, thanks to Reddit users.
This moment isn't the only time Musk's tweets led to a spike in certain interest.
For example, Musk had a role in helping GameStop's share price to rebound when it slightly dipped, when he tweeted "GameStonk" and linking it to the WallStreetBets Reddit community.
Previously, he also tweeted about Dogecoin and also Bitcoin, sending their price high.