The reason an aggregator’s return is a bet on other bets

An aggregator offered one clean headline rate, presented as a simple product. Behind it, the aggregator deposited into protocol A, which lent to protocol B, which relied on protocol C’s stablecoin and D’s oracle. The single rate was the net output of a tower of dependencies, and a failure in any one — an exploit, a depeg, a freeze — would cascade to the depositor. The clean number concealed a stack of correlated risks, each borrowed from a protocol the depositor never chose.

What everyone sees

A depositor sees one rate from one interface and reads one product with one risk: deposit here, earn this. The single figure implies a single, contained strategy. The depositor evaluates only the aggregator’s front door, not the chain of protocols behind it, and assumes the risk is whatever this one platform carries, not the sum of every platform it silently routes through.

What is actually happening

Composability stacks protocols, and stacked protocols stack their failure modes. Research on systemic risk in DeFi shows that layered dependencies create correlated, hard-to-see exposures, where the failure of a base layer propagates upward through everything built on it. The aggregator’s single rate is the residual of many underlying positions, and its risk is the union of all their risks — a portfolio of counterparties compressed into one number that names none of them.

Why it stays hidden

The hidden mechanism is the compression of many risks into one figure. The aggregator’s interface shows a net rate and hides the dependency chain, so the depositor sees one bet where there are several nested ones. Each hidden layer can fail independently, and their correlation means they can fail together. The simplicity of the displayed return is exactly what conceals the stacked fragility beneath it.