The point is that the FX market at the retail level is way too fragmented, so when you register with a broker you are not competing in the WHOLE market you are just competing with other customers that registered with that specific broker. Hence price movements on the wholesale level are not reflected on the retail level among all brokers equally.
the euro/$ could drop by 20 pips on the wholesale level and it will drop on your broker screen by only 10 pips and on another broker by 14 pips
the euro/$ could drop by 20 pips on the wholesale level and it will drop on your broker screen by only 10 pips and on another broker by 14 pips