MemCast
MemCast / episode / insight
Regime‑dependent models must be re‑trained frequently because market dynamics change faster than data accumulates
  • Nang describes how a model that performed well during a stable regime can break when a new regime (e.g., credit crisis) emerges.
  • He cites the 2007‑2008 credit‑market stress as an example where previously profitable statistical arbitrage collapsed.
  • Because regimes shift, relying on static parameters leads to rapid decay of edge.
  • Continuous monitoring and adaptive re‑training are essential to stay ahead of regime change.
Rishi NangTitans Of Tomorrow01:06:18

Supporting quotes

The credit part of the book is blowing up because the credit market is blowing up and so they need to raise cash to meet margin calls... they're moving markets with market impact because they're selling. Rishi Nang
If the edge is gone, what should happen is that the time it takes for the thing to move in the direction that you expected goes down a lot. It moves there much faster. Rishi Nang

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Overfitting, Underfitting & The Small-Data Problem

Nang explains why traditional machine-learning pitfalls are amplified in finance: limited data, regime shifts, and the temptation to over-customise models for specific assets.

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