GStock calculates the Yield based on the following formula:

Where:

• Closing Price (SELL-1) - the stock’s closing price on the next trading day after the SELL signal was initiated. If for example the SELL signal was calculated on August 1st, then SELL-1 is the closing price of the next trading day (usually August 2nd). The reason why GStock calculates the Yield in its backtests in this way is that the calculations of BUY and SELL signals are done at the end of the trading day, and therefore an investor that would have followed this investment strategy would have had to wait for the next trading day in order to sell the stock. In this way, GStock simulates a real investment environment.
• Closing Price (BUY-1) - the stock’s closing price on the next trading day after the BUY signal was calculated. If, for example, the BUY signal was calculated on June 1st, then BUY-1 is the closing price of the next trading day (usually June 2nd). The reason that GStock calculates the Yield in its backtests in this way is that the calculations of BUY and SELL signals are done at the end of the trading day, and therefore an investor that would have followed this investment strategy would have had to wait for the next trading day in order to buy the stock.
• - 0.2% - When calculating the Yield, GStock reduces 0.2% from the gross Yield achieved in each transaction, assuming transaction fees of 0.1% that an investor would have paid for each purchase and for each sell when applying the investment strategy.

For example: