How do you mark a heat rate to market? Letâs say I enter into a 10MW 7x24 HR swap for November at 8. So if I pull my position apart, I have a long power exposure of 30.5 days x 24 hours/day x 10MW = 7,320MWhâs, and a short gas position of 7,320 x 8 = 58,560MMbtuâs. So now how do I mark it? Do I hold one leg constant? Do I mark both legs? Lets say I look in the market and see my exact HR trade for 7 now, instead of 8. Holding power constant, I could say that I am short 7,320 MMbtuâs more than I needed to be, so does that become the basis for my loss? 7320 x what gas price? Current?