Bitcoin ETFs have picked up billions since their launch last week.

Why it matters: In just four trading days since listing on exchanges, investor flows in some of 10 are stacking up to broad-market funds, according to Bloomberg Intelligence data.

The big picture: It's too early to crown any one of them bitcoin ETF supreme. Many of the traditional finance venues — where these products would be bought and sold — tend to go slow in determining which, if any, they should offer. (Blame it on compliance.)

• At the same time, the leaders are emerging.

Zoom in: Nine spot bitcoin ETFs, plus Grayscale's converted trust, received the milestone nod from the SEC to list last week.

• Three of them — BlackRock's IBIT, Fidelity's FBTC and Bitwise's BITB — land in the top 10 in year-to-date flows.
• That puts them in the ranks with the $400 billion-plus asset iShares Core S&P 500 ETF and $980 billion Vanguard S&P ETF.
• Sure, starting from zero is an advantage. But there's been plenty of investor cash on the sidelines, waiting for a place to work.

Between the lines: Grayscale's converted GBTC fund has seen outflows. And while its 1.5% annual fee is the priciest of the bunch, there could be more going on there than just investors trading into cheaper products.

• Folks who bought GBTC at a discount before it was converted from a trust (when shares were trading below the underlying bitcoin) might be eager to take money off the table now that the ETF version has closed that gap.
• Meanwhile, GBTC is a substantial asset for more than one firm in bankruptcy, and at least one, Sam Bankman-Fried's collapsed FTX exchange, could be selling it now for creditors.

What we're watching: There could be more fund launches on the way.

• Exchanges have filed to list options on those new bitcoin ETFs (we told you this would happen).
• Other ETF shops have filed to launch new types of bitcoin ETFs: Inverse, leveraged, covered calls.

The bottom line: If there was any question about whether the traditional asset managers' bitcoin gambit was for naught, check out the numbers — they don't lie. (Never mind that bitcoin itself seems largely unmoved by Wall Street's early triumph.)

Go deeper: FTX's estate has 22 million units of GBTC to sell