Grayscale Bitcoin Trust's shares jump after first inflow since January

GBTC saw inflows of $63 million on Friday, according to investment management firm Farside Investors. It has $18.08 billion in assets under management (AUM), according to its website.

But its position as the biggest spot bitcoin ETF by AUM has come under threat from BlackRock's iShares Bitcoin Trust, which manages $16.91 billion, according to its website.

Grayscale said in March that it would seek approval from the Securities and Exchange Commission to spin off a portion of GBTC's assets into a new, lower-fee Bitcoin Mini Trust. However, the company has yet to determine the fees the Mini Trust will charge.

Spot bitcoin ETFs offer investors exposure to bitcoin without the need to hold it directly. They were approved by the SEC in January after being rejected for a decade.