BlockBeats News, May 21st, according to Coinglass data, Coinbase's Bitcoin Premium Index has been in a negative premium for 6 consecutive days, currently at -0.0919%. The continuous outflow of Bitcoin from Coinbase's spot ETF highlights the weak buying power in the U.S. market.

The Coinbase Bitcoin Premium Index is used to measure the difference between the Bitcoin price on Coinbase and the global market average price. A negative premium usually indicates significant selling pressure in the U.S. market, a decrease in investor risk appetite, a rise in market risk aversion, or capital outflows.