The performance of a signal is calculated differently, depending on the type of signal.
The open operating signal performance is calculated by dividing the market closing price of the financial instrument subject to the operating signal and the opening price of the signal.
If the signal has been opened at market price, the opening price is penalised by applying a 0.1% slippage, if referring to stocks or commodities, or 0.05%, if referring to Forex and bonds. As long as the signal is not closed, the slippage (as explained above) will also be applied to the closing price.
If the signal has been opened in limit mode, the slippage is not applied to the opening price but only to the closing price.
The performance of a closed operating signal is calculated by dividing the closing price of the signal by the opening price.
The slippage application depends on how you open or close a signal: if at market, it will be applied according to the methods already explained above; if at limit, it will not be applied.