Backtesting is not only a way to check signal accuracy, but also a tool to continually improvement. Data can be used for self adjustment as each stock have a individual behavior. Accuracy and return is not the same. A stock signal may provide low statistical accuracy, but the signals may prove high return in average. Sharp market dips or fundamental changes (earning reports, news updates etc), may force a short term reaction and disturb the signals (Signals may jump quickly from buy to sell, just to return to buy).
|2019-01-07 - 2019-01-18||BUY||-1.57|
|2019-01-04 - 2019-01-07||HOLD||5.36|
|2018-12-17 - 2019-01-04||SELL||1.04|
|2018-12-14 - 2018-12-17||HOLD||0.84|
|2018-12-13 - 2018-12-14||SELL||0.42|