Confusion with Nadex balance with spreads

#1

This is my demo trade: Your demo order has been executed

Your order was executed on: Wed May 18 11:25:43 EDT 2016. The details of your matched trade are shown below for your reference:

Trade Details: Contract: Crude Oil (Jul) 48.25-49.75 (12PM) Expiration: Wed May 18 12:00:00 EDT 2016 Direction: SELL Quantity: 1 Price: 49.08

Your positions and balances have been updated. The transaction number assigned to this trade is: 201605181055FH2T00078432O.

Your demo position has settled

Your position in the Crude Oil (Jul) 48.25-49.75 (12PM) contract has settled. The details of your settled position are shown below for your reference:

Settlement Details: Contract: Crude Oil (Jul) 48.25-49.75 (12PM) Quantity: -1 Expiration Value: 49.270 Payout Amount: $48.00

Your positions and account balance have been updated accordingly.

But when I look at my demo balance on Nadex it only went down $20.8 which I understand (49.27-49.08 plus 1.80 commission). My question is why did nadex state that payout amount is $48.00?

#2

When you let a spread expire and its in between the range, your profit will be the difference in dollars between the closing price and the floor/ceiling. So the 49.75 - 49.27 = 0.48

#3

Your payout email from Nadex does not show profit amount. it shows the total amount credit back to your account. When you enter into a spread trade a certain amount of money taken out of your account as margin to enter the trade. Then once it expires the amount of money put back in could be smaller or greater than the amount they took for margin based on profit or loss. For example they take out $30 for margin to enter the trade. The trade profits $10. They put back in $40 to your account…minus fees… The opposite would be the case if a loss