how to stop my positions after making a certain gain or loss : Let's assume that I took 5 positions, short or long, I would like to close them all automatically after making a total gain of $ 100 ... I don't know how to do that ... Thank you (I'm sorry my english is so bad...)
Use a limit order. A bracket order will allow you to place an opening limit order followed by a another other which becomes active once the opening order is filled.
If you've got a MT4 account running on a PC live, then you could get that to calculate and update limit sell orders as you add positions so you hit your exit target. Sure other brokers off coding which would enable to.
Brokers will vary; exchanges vary with acceptable native order forms by type of underlying asset; but the magic words you're looking for are Bracket, Trailing Stop, and Trailing Stop Limit. Learn the particulars of those (as presented by your broker, according to the applicable exchange rules), and the rest will be plain. [EDIT] "Ah-HA!!" After reading Tomorton's reply below, I now understand better what the OP sought. And so, Tommorton's answer is much better. [EDIT]² "Hah-hahhhhhh!" IB's TWS has a BasketTrader set-up that, while I don't use it, I understand it to take multiple positions and move them -- even page-wise, as per Tomorton's response below. I have no idea about other platforms, but it certainly will be a *collection* of native orders, rather than anything recognizable as native by an exchange. (And therefore, "YMMV.")
There is no way on my platform so that you can set all positions to close simultaneously when the unrealised gain (or loss) reaches a certain total. This can be done manually by either closing all positions in sequence or by clicking on the "Close all positions" button if your platform has this.
Which broker are you using? Not all software tools have the same possibilities. I assume that you want to calculate the total profit of the 5 positions, and close all 5 positions if your minimum profit level (e.g. $ 100) has been reached. If you are with IB and know how to use their API then this is not so difficult to program. I don't know whether this would be possible in TWS though.
MT4 I've got the code for doing the same on the SL side only, easily adapted to also set the Limit Close profit side.