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Over‑customising parameters for a single asset leads to a slippery slope toward overfitting
  • Early quant models used a single parameter set across all instruments (e.g., trend‑following in futures).
  • Adjusting parameters per asset creates a “slippery slope” because each tweak is fit to past noise.
  • Nang notes that once you start over‑fitting, cross‑validation confidence is illusory.
  • The solution is to keep models as general as possible and only add asset‑specific tweaks when a strong, theory‑backed reason exists.
Rishi NangTitans Of Tomorrow00:45:27

Supporting quotes

If you start adjusting the parameters for this and that, it's a slippery slope towards overfitting. Rishi Nang
You got confidence from a cross validation that this thing works across all the instruments. And if it only worked for these instruments, you just didn't believe it. Rishi Nang

From this concept

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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