Tell a real edge from a lucky backtest.
Run enough variants and a worthless strategy will eventually post a great Sharpe by chance. These free, browser-based tools measure whether your result survives the number of tries behind it — and whether your sizing will survive the drawdowns ahead.
The tools
Deflated Sharpe Ratio
Enter your Sharpe and how many variants you tested. See the probability the result is real, not the best of many tries.
Open calculator →Position Size & Risk of Ruin
A Monte Carlo of your edge over the next N trades: risk of ruin, expectancy, Kelly fraction and the spread of outcomes.
Open calculator →Net-vs-Gross Cost Calculator
How spread, commission and slippage turn a gross winner into a net loser — and the win rate where it flips.
Open calculator →Start here
Why your best strategy is probably the luckiest one
The mechanics of backtest overfitting, three real failure cases from hands-on research, and the toolkit — DSR, PBO, purged walk-forward, CPCV — that separates a genuine edge from luck.
Read the guide →How we validate
Every tool here comes out of a real research workflow, not a content brief. See the seven-step process and the principles it won't break.
Read the methodology →How we work
No advice, no signals
Methods and tools, never "buy this." There are no trade ideas here.
Costs always modelled
A result that only survives at zero cost is not a result.
Every trial counted
The number of variants tested is part of the result, not a footnote.
Approximations disclosed
If a number is an estimate, the tool says so on screen.