U.S. Bitcoin ETFs are shooting up: more than $1.38 billion has flowed into BTC funds since Monday. It looks like BlackRock and Fidelity are stepping on the gas in a big way now.

They are back: the U.S. Bitcoin Spot ETFs are finally reporting back after a long summer break and are now giving BTC investors hope for the start of a new bull run. Since the exchange opened on Monday, as much as $1.385 billion has been put into the 11 BTC index funds, according to new data from Farside Investors.

Making the biggest impression are the two Wall Street giants BlackRock and Fidelity, which are trailing the competition by leaps and bounds. BlackRock's iShares Bitcoin Trust drew $761.7 million in net inflows, while Fidelity's Wise Bitcoin Trust pulled in $289.1 million. Despite the positive results, other players such as Bitwise, Arkinvest or VanEck cannot keep up with this pace.

Currently, BlackRock manages some 381,000 BTC, worth $24.6 billion. With this, Larry Fink's company now controls 1.92 percent of the total circulating supply of Bitcoin. Second-place Fidelity's index fund controls about 184,500 BTC, worth $11.9 billion. However, this market dominance of the financial giants may also have a downside, which is that they have/gain too much power.

950,781 BTC: the Bitcoin treasury of ETF providers

The trend seems unstoppable - ETF providers' managed crypto assets are steadily growing. Together, they currently manage 950,871 BTC, with a total value of a whopping $63.75 billion. That BTC funds last Monday saw the highest net inflows since June could well be the start of a new ETF mega wave.

In August, Morgan Stanley became the first major New York bank to announce that their financial advisors may now offer wealthy clients BlackRock and Fidelity's Bitcoin ETFs. Goldman Sachs, JPMorgan or Wells Fargo are no doubt watching their competitors' first successes with interest - and may soon follow if they see profit opportunities.

Not only accelerated adoption by institutional investors, but also the U.S. central bank's interest rate cut could give Bitcoin ETFs wings by the end of the year. Falling interest rates on stable U.S. government bonds will encourage many investors to move their capital back into more volatile assets such as Bitcoin or tech stocks.