The spread between spot and futures Bitcoin prices continues to narrow, leading to a decline in institutional basis arbitrage trading using spot Bitcoin ETFs. This shift reflects changes in the structure of the crypto derivatives market. Data shows that open interest in Bitcoin futures on the CME Group has fallen below $10 billion for the first time since 2023, now trailing Binance. This trend is attributed to a decrease in basis and annualized returns, along with rising trading costs, which have reduced the appeal of ETF-futures arbitrage, rather than an overall withdrawal of institutional funds from the crypto market.