European lunch break - Low liquidity?

So I've noticed that there is often a flat period before the us open. Is this related to some kind of european lunchbreak or just waiting for the US to open?

Yes, from 8:00 Frankfurt open, 9:00 London Open, to 11:00 then breakfast, lunch time, to 14:00 NY Open. Have a nice day =)

Not true, not always. Sometimes u see at 11:00 or 12:00 high volatility.

Yes, not always happens, although I think it is more due to the waiting for the US opening than to any kind of lunch break.