2min chapter

Better System Trader cover image

185: How to avoid creating trading strategies that degrade quickly - Timothy Masters

Better System Trader

CHAPTER

Why Is Mary's Out-of-Sample Performance Now Biased?

For each of them, this performance on the most recent year is an unbiased measure of the quality of their system. It's unbiased because this data never went into their development process. But suppose you had decided in advance that you were going to trade Mary's system, even if John's was better. Her out-of-sample performance is now optimistically biased. How did that happen? The answer is that you are about to trade, in quotes, the better of John and Mary's system.

00:00

Get the Snipd
podcast app

Unlock the knowledge in podcasts with the podcast player of the future.
App store bannerPlay store banner

AI-powered
podcast player

Listen to all your favourite podcasts with AI-powered features

Discover
highlights

Listen to the best highlights from the podcasts you love and dive into the full episode

Save any
moment

Hear something you like? Tap your headphones to save it with AI-generated key takeaways

Share
& Export

Send highlights to Twitter, WhatsApp or export them to Notion, Readwise & more

AI-powered
podcast player

Listen to all your favourite podcasts with AI-powered features

Discover
highlights

Listen to the best highlights from the podcasts you love and dive into the full episode