Consider that you have taken position of current month MINIFTY
at 5150.
Say,First day it closed at 5190 then MTM 20*(5190-5150)=800.
Example:
Code:
close MTM
5190 800 (5190-5150)*20
5200 200 (5200-5190)*20
5260 1200 (5260-5200)*20
5250 -200 (5250-5260)*20
TOTAL= 800+200+1200-200=2000
The total 2000 is same as (5250-5150)*20 ,that is
(Current price-your price)*20.