Tesla CEO Elon Musk's act of tagging the world’s biggest cryptocurrency Bitcoin in his Twitter biography caused it to soar as much as 14% to a two-week high.

Musk wrote simply “#bitcoin” in his biography on the social media site. The cryptocurrency was trading at $37,800 as of 9:36 a.m. GMT.

On Jan. 11, Bitcoin tumbled 20% in its sharpest fall since March. It lost a fifth of its value, dropping down to $30,500.

The billionaire entrepreneur, followed by 43.7 million Twitter users, has a history of making market-moving comments on the site.

GameStop Corp, which has been at the center of a retail trading frenzy, surged 50% on Tuesday after Musk tweeted “Gamestonk!!”, along with a link to the Reddit Wallstreetbets stock trading discussion group.

There, supporters affectionately refer to him as “Papa Musk.” “Stonks” is a tongue-in-cheek term for stocks widely used on social media.

In December, Musk asked about the possibility of converting “large transactions” of Tesla’s balance sheet into bitcoin, in a Twitter exchange with a well-known advocate for the digital currency.