The US spot Bitcoin ETFs have witnessed significant outflows in recent days, totaling $145 million in net outflows on Monday alone. This trend has brought the total assets under management (AUM) to under $15 billion, a significant decline from the previous month. The outflows are largely attributed to the Federal Reserve's decision to maintain interest rates at 5.25%, signaling a potential prolonged period of high rates.

Fidelity's FBTC led the outflows, with over $92 million worth of assets withdrawn, followed by Ark Invest and 21Shares' ARKB, which saw $50 million in outflows. Grayscale's GBTC and VanEck's HODL also experienced significant outflows, totaling $4 million each. In contrast, Bitwise's BITB saw meager inflows of $3 million, while BlackRock's IBIT had zero inflows.

The Fed's decision to maintain interest rates has led to a shift in market sentiment, with investors becoming increasingly risk-averse. As a result, Bitcoin investment products have seen significant outflows, totaling $620 million in the past week alone. Short Bitcoin funds, however, saw inflows of $1.8 million, indicating a growing bearish sentiment in the market.

The decline in Bitcoin's price, coupled with the outflows, has led to a decrease in global assets under management, falling from $100 billion to $94 billion. Trading volumes have also decreased, with global digital asset investment product trading volumes reaching $11 billion, significantly lower than the yearly weekly average of $22 billion.

The initial enthusiasm surrounding spot Bitcoin ETFs seems to be waning among institutional players, who are now awaiting another macro catalyst, such as rate cuts, to drive capital inflows back into the market. The current trend suggests a challenging period for Bitcoin ETFs, as investors become increasingly cautious in the face of uncertainty.