How is the initial margin (IM) on open position is maintained?
The same margin % applicable for orders will be levied at position level also. Position level margin is arrived at by applying the IM% on the value of net open position. For example, you have open buy position in Fut – ACC- 26 Mar 2002 for 100 shares @ 150 and IM % for ACC is 25%. In that case, margin at position level would be 15000 * 25% = 3750/-. Moreover, benefit of calendar spread margin may also be available to you in case of spread position.
