Stress test: it measures how robust a trading strategy is, which is an indication of whether or not the strategy is over-fit. While any variable that affects a trading strategy's results can potentially be the subject of a stress test
The basic idea is to see what happens when small changes are made to the strategy inputs, price data, or other elements of the strategy or the trading environment. A robust strategy exhibits a proportional and relatively muted reaction to such changes, whereas a strategy that is not robust will react disproportionally and sometimes fail outright when small changes are made to its inputs or environment.
It helps to settle our mind for issue like internet failure, terminal issuesor health issues ,etc..where we miss trades.Since trending trading strike rate will not exceed 40%,never think that after performing this we get a weekly,daily,or hourly earning machine.