I have read a number articles about MVA, this is the effectively the funding cost of the initial margin, which has become important because of the rise of central clearing and because new rules on Bilateral OTC derivatives requiring IM and VM.

-IM should be static for the life of an individual trade, however manner its is calculated initially (eg 10 day VAR) right?

-Why is there a need to conduct a simulation exercise to calculate the funding cost of this IM if its known?

I get CVA and FVA because they are based on future MTM's, which are simulated to give an estimated exposure or funding requirement, not clear on MVA