3 of 4 checks run · all 3 passed, and returned more than buy and hold.
Bollinger band reversion · 4 rupee currency pairs
It returned +1.7% in total over the test, after costs; buying and holding over the same period returned +0.5%, 1.1 points less. It kept making money on the months it wasn't tuned on (+0.5%). The nearby-settings check wasn't run (it isn't run on a group of stocks), so this doesn't show whether the result depends on the exact settings. With the trades in a worse order, the worst fall stayed close to the one it had. 32 trades, enough to judge.
The rules: Enters when the price drops below the lower Bollinger band (20, 2); leaves when it closes back above the middle band.
StratLab ran these rules through its own backtest on every stock in the group, after costs, and through four checks: unseen years, nearby settings, a bad-luck drawdown and enough trades. The page shows the return beside buy and hold and the result of each check. A verdict describes the past, not what comes next, and nothing here is investment advice.