The Bloomberg 500 Is Not a Benchmark. It's a Toll Booth.

When Bloomberg announced its latest reconstitution of the Bloomberg 500 index — swapping out companies, adding names like Rocket Lab, Affirm, and SoFi — the press release read like a routine housekeeping memo. The kind of notice that gets published and immediately forgotten.

But if you look at what Bloomberg is actually building here, it is not a benchmark. It is a toll booth.

The B500 is Bloomberg's attempt to enter the most quietly profitable business in finance: the index provider industry, where firms that publish lists of companies collect licensing fees from ETFs that track those lists. The industry generated over $6.5 billion in revenue in 2023, with profit margins of 60% to 70%. The S&P 500 alone — maintained by a small committee at S&P Dow Jones — generates hundreds of millions a year in fees from ETFs like SPY and VOO, with a present value measured in the billions.

An index is a remarkably simple product to create and an enormously valuable asset to own.

Here is how the plumbing works. An index provider publishes a list of companies and the rules for how those companies are weighted. ETF issuers — BlackRock, Vanguard, State Street — license that list and build funds that buy those stocks. The ETF issuer charges investors an expense ratio (SPY charges 9 basis points, or 0.09% annually). But a chunk of that fee never stays with the ETF issuer. For SPY, about 3 basis points of that 9 flows to S&P Dow Jones as a licensing fee, plus a $600,000 flat fee. When SPY had $400 billion in assets, that was over $120 million a year paid to the index provider for maintaining a list.

In academic terms, research finds that about one-third of total ETF expense ratios go to index providers, and roughly 60% of those licensing fees are pure markup above the cost of maintaining the index. The market is highly concentrated — five providers control about 95% of the market — and the brand name matters more than you'd expect. Investors gravitate toward familiar index brands even when the underlying methodology is essentially identical.

So what Bloomberg is doing with the B500 should be read as a play for that licensing revenue stream.

The B500 positions itself as a "purely rules-based" alternative to the S&P 500, which uses a human committee to make final calls on membership. That committee has made headlines for excluding companies that technically qualified — like Strategy (formerly MicroStrategy) earlier this year, or Tesla in 2020, which was snubbed, dropped 21%, and was eventually added three months later. The Bloomberg team explicitly frames the B500 as different because it does not have a committee. If you meet the quantitative criteria, you get in. Period.

That is a genuine distinction, and it is worth understanding what it actually means for investors.

The S&P 500 committee can exclude a company that meets the numerical thresholds but fails a qualitative judgment — "Is this company really a core part of the U.S. economy?" The B500's rules-based approach removes that filter. The trade-off is straightforward: fewer surprise exclusions, but also no safety net against companies that are technically large enough but operationally weird enough that you might not want them in your broad-market basket. Some of the companies added in the August 2025 reconstitution illustrate the difference. Rocket Lab, trading around $66 with a $40 billion market cap and negative earnings, would have been a natural candidate for committee scrutiny. Under a rules-based system, it just gets in.

This is basically the same debate that happens every time someone compares mechanical screening to human judgment. The committee introduces opacity and potential for manipulation — a committee member was prosecuted for insider trading in 2020, trading on advance knowledge of index changes. The rules-based approach introduces its own opacity: the exact rules matter enormously, and companies that sit near the thresholds become the real beneficiaries, not some abstract ideal of fairness.

But the structural point for an ordinary investor is not about methodology. It is about whether Bloomberg can actually build a product that ETF issuers will pay to license.

And here is where the story gets more interesting. Because the index provider business is not just about having a good index — it is about having an index that someone is already tracking. The S&P 500 index has over $10 trillion in assets tracking it. That number is not a reflection of whether the S&P 500 is the best way to weight 500 large U.S. companies. It is a reflection of the fact that it was the first major broad-market index, and the entire passive investing industry was built around it. Switching is not just about being slightly better — it is about convincing trillions of dollars of capital to move to a new label.

In a Federal Register filing for B500 futures, MIAX described the B500 as providing "another instrument to hedge the broader U.S. equity market in the event that there is a disruption to existing market benchmarks." That is a telling way to frame it. The B500 is not positioning itself as the new S&P 500. It is positioning itself as the S&P 500's backup plan.

There are futures contracts on the B500 through MIAX, which is the first real step toward an ETF tracking the index. But as of now, there is no major B500-tracking ETF with meaningful assets. Without that, the licensing revenue story is not a story yet — it is a pipeline.

For the ordinary investor, what does any of this mean?

If you are wondering whether you should switch from an S&P 500 fund to a B500 fund, the answer is that you probably cannot yet, and when you can, the difference between them will be marginal. They will track roughly the same 500 large U.S. companies, weighted by float-adjusted market cap, with slightly different membership on the edges. The rules-based approach may pull in a few more growth-oriented or less established companies, and exclude a few that a committee would filter out, but for a broad-market allocation, the tracking error will be small.

The more useful way to think about the B500 is as a small crack in what is essentially a monopoly. The index provider market is one of the least competitive corners of the financial system. Bloomberg — which already owns the Terminal that every institutional trader uses — has the distribution, the data infrastructure, and the incentive to chip away at S&P Dow Jones's position. It is a slow game. The economics are on Bloomberg's side if they can get even a fraction of S&P's licensing revenue. The question is whether they can overcome the network effects of an index that has been the default for decades.

The reconstitution announcements — "Bloomberg 500 adds ten companies, here they are" — are not really about the companies. They are about showing that the index is alive, that it is being maintained, and that Bloomberg is serious about building something that issuers might eventually pay to use. The companies on the list are the product. The licensing fees from future ETFs are the business model.

And in the index provider world, having the second-biggest list is still worth something.