BlackRock's Bitcoin ETF Just Dethroned S&P 500 Giant: What's Going On?

BlackRock’s iShares Bitcoin Trust (IBIT), the firm’s flagship spot Bitcoin ETF, has officially overtaken SPLG, a core S&P 500 tracker with years of market presence behind it, to move into fourth place for year-to-date inflows

As Bloomberg analyst Eric Balchunas says, the move is more than just a symbol. It shows a change in how big investments are divided between traditional shares and regulated crypto products.

So far in 2025, IBIT has brought in just over $13.75 billion in net inflows, slightly edging out SPLG at $13.74 billion, according to Balchunas. That margin might seem small in dollar terms, but the bigger picture is hard to ignore: IBIT is still really new, only 18 months old, but it is already outperforming some of the most well-established passive products on the U.S. market

Even more impressive, it ranks fifth in cumulative three-year flows — a leaderboard it was not even eligible for until recently.

Vanguard’s VOO is top of the list, and it is having a record-breaking year. It pulled in almost $82 billion in 2025, with June alone making that entire figure — a one-month haul that would be career-defining for most funds

But even though VOO is really strong, it is important to remember that the Bitcoin ETF is now up there with the big dogs in equity indexing. As Michael Saylor pointed out when he looked at the data, if things keep going the way they are, IBIT could soon be in the lead.

Balchunas did not dismiss the possibility, even while acknowledging the absurd pace of flows into VOO. Crypto is still risky, but it is obvious that big investors are not waiting for the perfect conditions — they are getting into Bitcoin in the cleanest and most institutionally acceptable way possible.