"The Osprey Bitcoin Trust's (OBTC) bitcoin is held at Coinbase Custody," tweeted Osprey founder and CEO Greg King late Monday morning. King went on to reveal the public address of the funds.

The Osprey trust has around $46 million in assets under management (AUM), far smaller than the Grayscale Bitcoin Trust's (GBTC) $10.5 billion. Both funds trade at 40%+ discounts to their net asset value (NAV) – a figure that summarizes the per-share value of their underlying holdings.

Grayscale is owned by Digital Currency Group (DCG), which is also the parent company of crypto investment bank Genesis Global Trading and CoinDesk. Thanks to the struggles of Genesis' crypto lending unit, Grayscale has come under some public pressure to provide transparency surrounding its bitcoin (BTC) holdings.

Citing security issues, Grayscale had decided not to disclose public address information, but did provide a letter from Custodian Coinbase confirming the security of all assets held there for Grayscale and saying holdings are accurately reflected in Grayscale's various public and private findings.