In the context of your parameters:
- Trailing Start: 50
- Trailing Step: 150
- Take Profit (TP): 200
- Stop Loss (SL): 0
Here is what would happen:
- When you open a trade, there's initially no stop loss since your SL is set to zero.
- If your trade moves in the favorable direction by at least 50 points (the trailing start), the EA will start to manage the stop loss level. It won't immediately move the stop loss to breakeven or to the trailing start level, it waits for the trade to move another 'trailing step' points in profit.
- When the trade is in profit by 'trailing start' + 'trailing step' (200 points in your case), the stop loss will be moved to the price level of 'trailing start' points in profit. So, after 200 points in profit, your stop loss would be moved to 50 points in profit.
- From this point forward, for every 'trailing step' points in profit (150 points in your case), the stop loss will be moved up/down by the same 'trailing step' points, always keeping a distance of 'trailing start' points from the current price.
So to answer your questions, you won't see the trailing stop on your charts until the trade is in profit by 'trailing start' + 'trailing step' points. Yes, the trailing stop loss will work even if your initial SL is set to zero. The trailing stop loss doesn't need an initial stop loss to function, it operates independently.
Please note that the trailing stop is managed by the EA on the trading platform and not by the broker's server, which means that it will not work if the trading platform is not running and connected to the internet. It's also worth mentioning that the 'stop loss', 'take profit' and 'trailing stop' levels are not guaranteed and in volatile market conditions, the price could gap and these levels might not be respected.