When trading a walk forward optimized strategy, it must be regularly re-trained and adapted to the current market situation, just as in the WFO process. For this, Alice has added the following lines to the script:

if(ReTrain) {
UpdateDays = -1;
SelectWFO = -1;
}

ReTrain is nonzero when the [Train] button is clicked during live trading. UpdateDays is the time period for automatically downloading new price data for the current asset from the broker's server, which is then used for the subsequent training cycle. If set to -1, the price data is updated to the current date. Alternatively, price data from a Zorro update could be manually copied into the History folder. SelectWFO tells Zorro not to optimize the whole simulation period, but only a certain WFO cycle; in this case, the last cycle (-1) that contains the new price data.

Clicking [Train] every couple of months will continue the WFO process during trading, and makes the strategy independent of external parameter settings - we have essentially a 'parameter-free' strategy. Can we really expect the projected annual return and monthly income when we let Zorro trade it this way? Maybe in the long run, but we'll still have long periods, as in 2011/2012, with no profit. In the next workshop we'll learn how to make strategy returns more steady and reliable so that Bob can really derive a regular income from them.

Zorro S is required for re-training executable strategies, such as the included Z strategies.

Re-training script-based strategies is also possible with the free Zorro version when new price data files are available for download on zorro-trader.com. Unpack the new price data file into the History folder of the trading Zorro, then start the optimization process as described above.