All major world stock markets crashed despite portfolio insurance being US-centric.

Evidence

By 1987, the technique was beginning to be adopted outside the United States, but nowhere else had it achieved anything like its scale in the United States. Since all of the world’s major stock markets crashed, by amounts often similar to or in some cases even worse than in the United States (Roll 1988), specific features of the U.S. market such as portfolio insurance might seem to be incidental. — Donald MacKenzie, An Engine, Not a Camera, 854

Categorization

• XREF: Connects directly to the performativity thesis’s weaker claim — if models were fully performative, markets without the model shouldn’t mimic its effects.