Quote from CodeX:
A few seconds? I am fighting for millisecond. it matters a lot with the strategies that i use. It makes all the difference.
Besides the importance, i would also like to understand the reason behind this anomaly. Is it always like that, or is the fault from my side?

Quote from Satan's Helper:
Most feeds have a small delay.
As for a strategy that relies on speed. You really need to think about that. You are fighting with people who have some serious cash and don't mind blowing a few mil to get what they want.
In the long run you can't win if speed is your advantage.
Quote from CodeX:
That is correct, i was comparing two data feeds; on one hand i receive 3 to 4 and sometimes more bid / ask quotes and on the other hand i have IQfeed with a 25% reaction time; it takes almost 1 second and sometimes more (sometimes less).