A spreadsheet tells you what you made. This tells you whether the way you traded is repeatable — measured in R, so one big win can't disguise a losing method.
Your rules, scoredWrite down the setup you say you trade. See how you do when you follow it versus when you don't — the one comparison a spreadsheet can't make.
Honest statisticsEvery figure states its sample size, and says "not enough data yet" instead of guessing. Findings are re-tested on trades they weren't found on.
Your data stays yoursNo broker password is ever asked for. Export everything at any time, and delete your account and its data in one click.