According to CoinGlass data, the Coinbase Bitcoin (BTC) premium index has been in negative territory for 31 consecutive days. According to data from the cryptocurrency data platform CoinGlass, the Coinbase Bitcoin (BTC) premium index has been in negative territory for 31 consecutive days. The index, recorded at -0.1353% in the latest measurement, suggests that Bitcoin demand in the US market may be weaker compared to global markets.