According to ChainCatcher, Grayscale official data shows that the management fee of Grayscale XRP Trust is 2.5%, using the CoinDesk Ripple Price Index (XRX) to provide a reference exchange rate denominated in US dollars.
As of September 11, Grayscale XRP Trust had assets under management of $247,921.68 and a net asset value of $10.73 per share.