So using indicators as a trailing isn't the same as using a trailing function because in execution, the EA (such as a H4 EA) will not be closing immediately when the Moving average cross over but waits till the next 4hr bar to close it. That's a very long wait.
Actually Trailing SL and an exit at a trend following indicator are very similar. Both the indicator exit level and the Trailing SL move at a new bar.
In both cases, the Expert Advisor closes a position at the SL or the indicator value calculated from the previous bar.
Thanks for the clarification.
I think you have highlighted the Key (definition) difference between EAS's Trailing and the Trailing function that is commonly known and understood by traders.
Understand how a trailing stop loss works. The trailing stop loss is a type of sell order that adjusts automatically to the moving value of the stock/forex. Most pertinently, the trailing stop loss order moves with the value of the stock/forex when it rises.
This is the definition most traders understood when we talk about trailing function.
However, EAS trailing function is not trailing at every price movement but trailing at Bar Open/Close difference.
Hence, it's important for users to know that when they are requesting for a Trailing Stop loss in EAS, they will Never get the trailing function that is commonly understood (track price movement by every price change) but only trailing difference between bar open and close because that's how the software work, using Bar data and not tick data. (correct me if I'm wrong).
I think it's important to understand how the software work (trade at every bar close/open) so that we don't ask for things that is beyond the "structural" system of the software. And we can start focus our energy on what is possible within the software's structural system.
Can Popov add a trailing function (by price movement) into the EA, yes of course he can but that would mean the backtesting result isn't reliable (but arbitrary) that would defeat the purpose of backtesting
Why trailing by price movement isn't possible with EAS, the primary importance to Popov is "Reliable Backtesting" and given the bar structure of the software, it's not possible to produce reliable backtesting result by price movement because the bar data (open, high, low, close) doesn't contain price movement information. Unless Popov were to change the software's structural system by incorporating tick data, or using lower time frame (bar) data to track how price move for higher time frame, then we can start looking at the possibility of having trailing by price movement. Otherwise, we have to compromise with backtest reliability which is of utmost importance to Popov and many other users.
And if trailing by price movement is important to you, it's time to think out of the box.