Modify Volume of a Market / Position Order

Fernando Carreiro  
Suminda Dharmasena: Can the volume of a market or position order be modified?

No, not after the fact! You can however, carry out a parcial close to reduce the volume, incurring whatever loss or profit results from that action.

You can also add to the volume by placing new orders, which will result in new positions for a Hedging Account, but the net result will be equivalent to that of a Netting Account which only ever holds one position per symbol.