# The incumbents: how BlackRock, Vanguard and State Street built moats
In 2009, a struggling asset manager called Barclays Global Investors was up for sale. BlackRock bought it for roughly $13.5 billion, absorbing the iShares exchange-traded fund (ETF) business in the process. That single deal turned BlackRock from a bond specialist into the largest asset manager on earth. By 2025 its assets under management (AUM: the total value of client money it invests) crossed $11 trillion. Add Vanguard (roughly $10 trillion) and State Street (roughly $4.5 trillion), and the "Big Three" control north of $20 trillion combined. All figures are widely reported estimates as of 2024 to 2025.
To put that in scale: that is more than the combined GDP of most major economies. And it sits mostly in products that charge almost nothing.
Start with the core distinction.
That fee, expressed as a percentage of assets, is the expense ratio. It is the single most important number in this sector.
The Big Three dominate passive. Vanguard and BlackRock (via iShares) are the two largest ETF and index fund providers globally, with State Street's SPDR business running the oldest US ETF, SPY, launched in 1993.
Here is the mechanism that makes this near-unassailable. Run a worked example.
Imagine two S&P 500 index funds. Both track the identical index, so their returns before fees are basically the same.
Annual revenue = $500bn x 0.0003 = $150 million.
Annual revenue = $2bn x 0.0003 = $600,000.
Both funds have similar fixed costs: compliance, technology, index licensing, custody, staff. Say that base cost is around $20 million a year to run a serious operation. The incumbent covers it easily and pockets $130 million. The challenger loses roughly $19 million.
The challenger's only lever is to raise fees. But the moment it does, it is more expensive than the incumbent tracking the exact same index. Why would anyone buy it? For a commodity product, price is almost the entire decision.
That is the cost moat. Scale spreads fixed costs across a vast asset base, letting incumbents charge near-zero while still earning billions. Challengers cannot match the price without bleeding cash, and cannot charge more without losing customers. The oxygen is starved.
There is a supplier in this chain worth naming. Index providers (S&P Dow Jones Indices, MSCI, FTSE Russell) own the intellectual property of the indices themselves. Fund managers pay them a licensing fee to track "the S&P 500" or "MSCI World."
This is a quiet power center. MSCI and S&P Global run high-margin businesses because every ETF tracking their benchmarks pays them. So even as fund fees race to zero, the index suppliers capture a durable slice of value. Watch the whole chain, not just the asset manager.
Vanguard has fought this by using in-house or lower-cost index arrangements where possible, another scale advantage smaller firms lack.
BlackRock and State Street are publicly listed companies. They answer to shareholders who want profit.
Vanguard is different. It is mutually owned: the funds own the management company, and the fund investors own the funds. There are no outside shareholders demanding a profit margin. In principle, Vanguard runs "at cost" and passes savings back to investors as lower fees.
This creates a structural race to the bottom on price that the listed rivals must follow. When Vanguard cuts fees, BlackRock and State Street often have to respond. For a challenger with venture backers or public shareholders wanting returns, competing against an entity built to make zero profit on fund management is brutal.
Learn the ownership model directly from Vanguard's own explanation of its structure.
Cost is only half the story. The Big Three also own the pipes.
Distribution: BlackRock's iShares ETFs are on every major brokerage platform and inside thousands of financial advisers' model portfolios. Once you are the default building block advisers reachreachThe number of unique people exposed to your message in a given period. Unlike impressions, reach counts each person once, no matter how often they see it.View full definition → for, incumbency compounds. New entrants have to earn shelf space one platform at a time.
Custody and servicing: State Street is less about retail funds and more about being a custodian bank, the firm that safeguards assets and handles the back-office administration for other institutions. It is one of the largest custodians in the world. This is unglamorous, sticky infrastructure with high switching costs. Clients rarely move it.
Technology: BlackRock built Aladdin, a risk and portfolio management platform. It does not just run BlackRock's own money. BlackRock licenses Aladdin to rival asset managers, insurers and pension funds who pay to use it. So competitors run their portfolios on the market leader's software. That is a second, separate moatmoatA lasting edge over competitors: a resource, capability or position they cannot easily replicate, letting a firm earn above-average returns over time.View full definition → and a growing revenue line that does not depend on fund fees at all.
Knowledge check
1. Why does the expense ratio function as the single most important competitive variable in the passive fund industry?
2. What is the core conceptual distinction between active and passive management?
3. Why does scale in passive investing create a self-reinforcing moat that is hard for new entrants to challenge?
4. Select ALL correct answers about why the flow of new investor money has been overwhelmingly moving into passive products.
Select all the correct answers.
5. Select ALL correct answers describing how a single acquisition can transform an asset manager's competitive position.
Select all the correct answers.
MapMapUsing software to automate repetitive marketing tasks and campaigns, enabling personalisation at scale across channels like email, web, and social.View full definition → the value chain and the tension becomes clear.
The interesting friction now is between the manufacturers and the distributors. When Fidelity offers a zero-fee index fund, it is not making money on the fund. It uses the fund as a loss leader to capture the customer relationship, then earns from cash balances, securities lending and other services. Distribution power is rising.
Because the Big Three passively hold huge stakes in nearly every large public company, they collectively cast enormous shareholder votes. Regulators and academics increasingly ask whether this concentration of voting power across competing firms is healthy. This is a live governance and competition debate in both the US and EU as of 2026, not a settled issue. It is arguably the single biggest political risk to the incumbents' position.
Yes, at the edges.
The lesson: nobody out-cheaps the Big Three on plain-vanilla index products. Challengers survive by going where the cost moatmoatA lasting edge over competitors: a resource, capability or position they cannot easily replicate, letting a firm earn above-average returns over time.View full definition → does not apply.