The Position History window contains information about all the trades that form the current state of a given net position and the profit/loss each individual trade has generated. Orders are shown in chronological order - higher-listed ones are the more recently executed. You can see the history of a position by right-clicking on the position in the Positions window / Orders list window / Chart window and then selecting Position History/Last orders from the Context menu which will appear:
As there might be hundreds of trades that form the current state of the position, the history is displayed in segments. The most recently executed trades are in the first segment, the next ones - in the second, and so on.
If we were to graphically represent how a position's net volume changes in time, it would look like this:
Each executed trade changes the volume of the net position, represented as a bar at the moment of execution of the trade. While you trade, the position changes its sign, and from positive becomes negative, and vise versa, or is sometimes neutralised (when its volume becomes "0"). Every time that happens, a so-called segment is created in the history of the position. So each segment contains the trades between two changes of the position's sign.
Information about the current segment is displayed in the top-left corner of the window. You can browse through the segments using the arrows.
The above panel allows you to see the history of another instrument by selecting it from the Instrument drop-down menu. Don't forget to press the Refresh button when you change the instrument.
The Close button closes the window.
The following information about the orders is displayed:
Last Position P/L chart button change the view, opens the Last Position P/L Chart. There you can see your P/L of the position at a given price of the instrument. The button on the left you can change the view on grid.
When you close a position, it will disappear from the Positions Window, but you can always check its history by right-clicking on the position's instrument in the Exchange Rates windows and selecting Position History/Last Orders from the Context menu.