Glossary
What is Sample size
How many trades stand behind a number. On 10–20 trades, Winrate and PF swing on a single trade; conclusions about a setup need several dozen.
How it works
Example
The model sample has 88 trades. One extra win would move Winrate from 28% to 30%.
Common mistake
Changing the system after five losing trades.
Read next
Related terms
Frequently asked questions
- Where can I learn Sample size step by step?
- In the Trading OS Academy: “Model stats without distortion”, “The result is not the excuse”.
- What is Sample size related to?
- Edge; Outcome bias; Winrate.
Plan versus outcome — for every trade
The Trading OS journal keeps the planned RR and the actual R of each trade side by side and computes expectancy from real results.
No sign-up — the journal runs in your browser; an account is only needed for sync.