Internet reports that spot bitcoin ETFs flowed out again in large quantities this week. Analysts believe that the core reason is that the premium of CME bitcoin futures has narrowed (the basis has dropped to about 4%), which has weakened the appeal of the "cash arbitrage" strategy, especially in the current situation. With 10-year U.S. bonds providing a risk-free return of about 4.3%, arbitrage funds are more inclined to shift to safer investments. There are other factors that have affected market sentiment, but essentially the adjustment of arbitrage strategies by professional traders is the key to capital outflows. Bitcoin's Realized Profit/Loss Ratio on the 30th did not fall below the trend line, suggesting that the bull market should still continue, and the current trend may be closest to 2017.