Coinbase's Bitcoin Premium Index has recorded a negative premium for six consecutive days, currently standing at -0.1644%, according to Coinglass data. This trend highlights ongoing outflows from Bitcoin spot ETFs and suggests a weakening buying demand in the U.S. market. The index measures the price difference between Bitcoin on Coinbase and the global market average. A negative premium often indicates stronger selling pressure in the U.S., declining investor risk appetite, and increased risk-off sentiment, contributing to capital outflows.