⚠ The Platform Can Put Its Own Fund In the ModelHigh threat

A model portfolio is a list, and the list is controlled by the platform, not by the manufacturer. Every large wealth platform in the United States now owns or has access to its own asset management capability, and every one of them understands that the model is where the manufacturing margin gets allocated.

The substitution is trivial for the platform and invisible to the client. Replacing one broad-market index fund with another changes nothing an investor would notice, and it moves the fee from BlackRock's income statement to the platform's. The switching cost that protects an institutional mandate — transition risk, fiduciary justification, board process — barely exists here, because the underlying exposure is identical.

BlackRock's defence is real but partial. It supplies analytics into the adviser desktop — BlackRock cites portfolio construction tools as increasing the number of advisers and retail investors using its products¹ — which gives it presence when models are built; and its funds are frequently the most liquid, which matters for a platform rebalancing at scale. But neither is a contractual claim on the slot.

The reason this belongs on the stickiness page is that model-driven flow looks exactly like loyalty from the outside, right up to the moment it does not. Assets arriving month after month with no visible sales effort are indistinguishable in the accounts from assets that are genuinely locked in.

The tell would be a step change in retail flows with no market event to explain it — which is what a model reconstitution looks like from outside the firm.