Well, my questions are quite simple to begin with:
1. As I understand it, to open or close a position you specify it the same way as a futures trade on any other exchange, except that instead of a prompt month you give a prompt *date*. Right ?
2. The quote data available from the LME usually includes quotes for spot, one month out, three months out etc. Let's say I enter a three months out position today on the basis of the "3 months" quoted prices. No problem. But if I then want to flatten it a week later, there aren't any quotes available pertaining to the prompt date of my position, because the "3 months" prompt date is now one week later than the prompt date of my position. How do you figure out a sensible price at that time ?