The ability to specify the % of your account you wish to allocate to a trade and then cTrader automatically gives you the relevant lot size/volume. For this to work you would need to specify the stop loss price so that cTrader can calculate the position based on your current account value, the current price and the stop price. For example, if I was trading a $2000 dollar account, I would like to specify a EURUSD trade of 0.5% of my account where the stop loss is 50 pips. cTrader would then autopopulate a lot size of 2k.

My idea was more to have the option to be able to run a script at Order exection time.

That would allow greater customization and flexibilty. For example I want to place a stop at 2*ATR(14) away from exection price that risks 1% of my capital and places a TP at 2:1 Risk reward ratio. Others may have different criteria for their stops.

Admittedly this may add a fraction of a second onto execution time for a script to run so is probably more useful for swing traders than scalpers. But would bean amazing feature to have.

This would def be such a frequently used feature! please do add this!

It would be really helpful, if the balance field in the the order mask popup would be editable... After setting the sl in pips and the risk tolerance (e.g. 0,5, 1, ...) the volume will be automatically calculated (rounded to 1k, 10k, 100k - perhaps adjustable via a settings parameter)

OR

Provide some increase/decrease functionality for volume field (similar to field sl in pips). So we can can increase volume, after setting a sl in pips, until our risk tolerance will be hit (instead of adjusting the volume field several times manually)

it is easy to code this function. I did it in my bots

We need this! Please add!

Only reason I still use MT4 is because Ctrader does not have this feature and on my MT4 I purchased a trade manager that can do this. So I use a bridge to ctrader I first create the order in MT4 then the calculated lot size is sent to ctrader for live execution. But if Ctrader can add this I'll be completely no longer need to use Mt4. Please add this feature. Thank you very much!

Any news on this??

What a ridiculous statement...you do have an initial stop, right? So you need to figure out the size of the position, otherwise how would you know how much are you going to lose if the trade goes against you and hits your stop?
This feature would merely save those of us who utilize proper risk management some time and hassle. It has got nothing to do with trailing stops. Also, if calculation of position sizing is too complicated for you, maybe you should stay away from trading the financial markets...

THE FACT YOU HAVENT DONE THIS IS BEYOND ME AAAAND RIDICULOUS