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Backtests showing markedly different results with $100mm instead of $10mm

Is anyone else getting this? The same algo with $10mm has low volatility and roughly 2% annualized returns (not great I know, it's a very low capital intensive model), but if I increase the portfolio size on the top right to $100mm and make the max/min notional 100x larger all of a sudden it craps the bed. I would have thought performance would have been better, not worse.

2 responses

Hi Ken,

There could be a number of reasons contributing to the difference performance. Possible exanations include:

  • Portfolio leverage
  • Order transactions and status of open orders
  • Slippage (when are orders being filled)
  • Ordering methods (are you using order_target_percent/value?)

Can you post your code so we can help you out? Or perhaps share sample code? I'd be happy to take a look!

Cheers,
Alisa

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Very likely it is trading illiquid things, and the slippage model is causing fills to stretch out over days