The fund flows for US Bitcoin and Ethereum spot ETFs are once again in focus. The latest data from December 30th shows that in this wave of market activity, institutional investors have exhibited a clear wait-and-see attitude — the Bitcoin spot ETF experienced a single-day net outflow of nearly $19.29 million, marking seven consecutive days of net outflows. Coupled with the Ethereum spot ETF's net outflow of $9.63 million on the same day, the total net outflow for both has reached $28.92 million.

Looking closely at the actions of major institutions reveals even more interesting details. Invesco's BTCO led with a single-day net outflow of $10.41 million; this fund has now accumulated a net inflow of $205 million. Following closely are BlackRock's IBIT and Ark & 21Shares' ARKB, with net outflows of $7.92 million and $6.66 million respectively, seemingly reducing their holdings at opportune moments.

However, Fidelity's FBTC went against the trend — recording a net inflow of $5.7 million yesterday, becoming the only BTC ETF product with a net inflow on that day. This fund has now accumulated a total net inflow of $12.1 billion, demonstrating institutional enthusiasm for long-term allocation.

As of now, the total net asset value of Bitcoin spot ETFs has reached $113.07 billion, accounting for 6.49% of Bitcoin's total market capitalization. The cumulative total net inflow has exceeded $56.61 billion. The situation with Ethereum is similar — the total net asset value of spot ETFs is $17.72 billion, representing 5.01% of Ethereum's total market capitalization, with a cumulative net inflow of $12.33 billion.

It is worth noting that the divergence within Ethereum ETFs is more pronounced. BlackRock's ETHA experienced a single-day net outflow of $13.28 million, with a total net outflow of $12.59 billion, while Fidelity's FETH recorded a net inflow of $3.65 million during the same period. This ebb and flow among institutions may reflect differing long-term expectations for the performance of these products.