Source
When this applies
when a market or system shows unusual internal divergence despite overall calm, and you suspect crowded, neutralized positioning is the cause
The takeaway
When low index-level volatility coexists with high internal/factor volatility, suspect that crowded neutral strategies have displaced risk from the aggregate into narrower, less visible pockets.
Why it works
Multi-manager RV funds tripled in AUM since COVID because high rates made market-neutral strategies (long book offset by short book, collecting collateral interest) extremely profitable; but as more funds chase the same shrinking pool of ~3,000 tradeable stocks (down from ~10,000, due to fewer IPOs and more buybacks), their neutralized factor exposures get crowded into unseen risks, producing violent unwinds in specific stocks/factors even while the index itself stays calm.
One level up
Hidden crowding doesn't disappear when you hedge it away — it just relocates to a less observed dimension of risk.
Where it stops holding
This stops working when rates fall enough that RV strategies lose their collateral-interest edge, reducing AUM growth and crowding pressure, or when the tradeable universe of stocks expands again (more IPOs, less buybacks).
Detail
approach: Trace unusual market internals (negative correlation, factor vol) back to structural causes: high rates -> RV strategy profitability -> AUM growth -> shrinking tradeable universe -> crowding -> violent single-stock/factor unwinds.
signals:- Index-level vol low while single-stock/factor vol high
- Multi-manager AUM growth concentrated post-rate-hike period
- Net negative equity issuance reducing the tradeable universe
rationale: Everyone neutralizing the same risk factors just pushes crowding into whatever dimension isn't being tracked.
In their words
with those combination of factors, plus the ballooning of AUM, plus leverage from PBs on top, you end up with this crowding out effect. And everyone will say, Oh, okay, hang on a second, it doesn't matter because I've neutralized everything. No, all you've done is push the crowding into other aspects of your portfolio.