Spot Bitcoin exchange-traded funds (ETFs) have had an impressive run since their launch last week, as inflows into the newly trading funds in the U.S. ETF market continue to pour in.

The 11 spot Bitcoin ETFs hold an estimated $28 billion in assets under management (AUM), largely thanks to the conversion of Grayscale Investments’ flagship fund – the Grayscale Bitcoin Trust (GBTC) – into a spot Bitcoin ETF.

GBTC owned around 3.4% of Bitcoin’s circulating supply at the time of its conversion, and while there has been some reshuffling of funds between GBTC and the other spot Bitcoin ETFs, net inflows into the asset class as a whole have been consistent through the first four days of trade. 

This means that, as far as commodity ETFs go in the U.S., spot Bitcoin ETFs have now surpassed Silver ETFs, which have around $11.5 billion in AUM, and are second only to gold ETFs that hold $95 billion in AUM, according to data from ETF Database. 

Ophelia Snyder, the co-founder of crypto investment firm 21Shares, said on X that development validated Bitcoin’s role as a reserve product. 

“Granted… if you had looked at BTC linked products prior to conversion to ETFs this would also have been true. But it’s good to see that this wasn’t solely investors arbitrage trading premium/discount,” she noted. 

The success of spot Bitcoin ETFs in their first week of trade hasn’t quite played out in price action, however, with Bitcoin falling to a low of $40,631 on Thursday. At the time of writing, the price had recovered slightly to around $41,200, but was still down 3% over the last 24 hours.