According to Odaily, official data reveals that as of May 20, Grayscale's Bitcoin ETF (GBTC) held 289,390.3453 BTC, while BlackRock's Bitcoin ETF (IBIT) held 277,716.00350 BTC. The gap between the two has narrowed down to 11,674.3418 BTC, with the market value difference also shrinking to approximately 1 billion USD (1,011,688,068.1 USD).

This development indicates a significant shift in the Bitcoin ETF market, with BlackRock catching up to Grayscale's previously dominant position. The narrowing gap in holdings and market value suggests increased competition in the Bitcoin ETF sector, which could potentially impact the future dynamics of the cryptocurrency market.

It's important to note that these figures are based on the most recent data available and may fluctuate due to the volatile nature of the cryptocurrency market. Investors and market watchers are advised to keep a close eye on these developments as they could signal significant shifts in the Bitcoin ETF landscape.