The catch is, $GBTC holders have been locked for such a long time, it's unclear what percentage just sells and who rolls over to another Bitcoin Spot ETF. Nobody in the right state of mind will stay with Grayscale and their 1.5% fees. As the price of #Bitcoin has gone down since the trading of the Bitcoin Spot ETFs started, it's likely that at least part of it is sold on the spot market, while the Bitcoin Spot ETFs buy OTC.