When a concentrated AI-focused fund began unwinding, the damage did not stay contained. Names with no operational overlap fell together, which is exactly what happens when a crowded trade discovers that its participants share one exit.
The episode is worth studying not because the thesis was wrong, but because the position sizing assumed liquidity that only exists when nobody needs it.
Highlights
- A concentrated AI fund unwound positions across a single week.
- Correlations between AI names spiked to near one during the selloff.
- Diversification inside a theme is not diversification.
Correlation is a liquidity phenomenon
During calm markets, chip designers, data-centre operators and model providers trade on their own fundamentals. During a forced unwind they trade on one factor: who owns them. Realised correlation across the basket climbed above 0.9 within three sessions, erasing the diversification investors believed they had.
This is the mechanism behind most theme-fund drawdowns. The portfolio looks diversified by ticker and is entirely undiversified by holder, and the second measure is the one that matters when redemptions arrive.
“You do not find out how crowded a trade is until you try to leave it. By then the information is expensive.”
The leverage was structural, not explicit
Little of the exposure came from margin. It came from private-round marks that could not be sold, from convertible structures that hedged with public equity, and from options positions whose dealers had to sell into weakness to stay flat.
Investors reading only the reported gross exposure would have concluded the book was conservatively run. The effective leverage sat in the plumbing, and it appeared only once prices moved far enough to trigger hedging flows.
Practical takeaways
Size positions against the worst plausible exit window rather than against average daily volume. If a position takes more than a few days to liquidate under stress, it is larger than the risk model believes it is.
Treat thematic exposure as one position regardless of how many tickers it contains, and set a limit at the theme level. The investors who came through this episode intact were not the ones with better forecasts; they were the ones with smaller books.