The daily On-Chain holdings (in BTC) for spot bitcoin ETFs with known On-Chain addresses, namely BlackRock (IBIT), the Grayscale Bitcoin Trust (GBTC), Grayscale Bitcoin Mini Trust ETF (BTC), Fidelity (FBTC), Ark Invest/21Shares (ARKB), Bitwise (BITB), Franklin (EZBC), Invesco/Galaxy (BTCO), VanEck (HODL), Valkyrie (BRRR) and WisdomTree (BTCW).