Fixed spreads in relation to spot variable spreads, how are they priced?

 
Hello, I would like to know how the fixed spreads from your dealing desk work in relation to the greater spot market quotes i.e. if your dealing desk is running a fixed spread of 2.5 pips how does that then correspond to the variable spread spot market, i.e. are your spreads fixed 2.5 pips from the variable spot bid price or fixed 2.5 pips from the variable spot ask price?

The reason I'm asking is because unless I can get historical tick data from your servers the best historical data I have is the Dukascopy bank spot data which has a variable spread and I'm trying to backtest a strategy factoring into account the benefit of your fixed spreads.

Thank you
 
The definition of spread is Ask - Bid. A fixed spread of 2.5 pips from the Ask makes no sense.
 
William Roeder:
The definition of spread is Ask - Bid. A fixed spread of 2.5 pips from the Ask makes no sense.




The spread is 2.5 pips.

The spread is 2.5 pips from the Bid

The spread is 2.5 pips from the Bid to the Ask

The spread is 2.5 pips from the Ask to the Bid

The spread is 2.5 pips from the Ask




THE SPREAD IS 2.5 PIPS.




Reason: