Well done MeiHua, ur TA can find the most volatile time if we average that.
But behind why market so volatile due to that time coz most high impact news release on that time.
And if we breakdown what the news i said above, it will be produce more news that makes why market so volatile on that time 
I would be wary of making such huge over arching generalizations on what other traders are doing. There are literally millions of strategies, and what you consider in your own analysis is not a benchmark for others. Consider this, if everyone was waiting for LO, and LO presented the best entry position. Then over 50% of the daily volume would occur within 2-3 hours of the LO, which it doesnāt. Also assuming HFTs are only 45% of this market ( they can be >80% in futures and equity markets where there is an exchange to track them) they are only considering the last few seconds at most. Commercials, and hedgers couldnāt care less about any intraday move, in either direction.
Although I do believe that news does play a role in the volatility spikes on any given day. These are mostly US based. The European news which would come out during their open, or mid day should have the same impact because its the other side of the currency pair. Usually there is small news everyday, but thats a baseline thats accounted for in every calculation. Not to mention the ratio of non news days to news days is huge, I havenāt counted them but i would guess thereās is at least 5 non news days (days without large releases like NFP, unemployment, Interest rates) to news days. So that volume and volatility is then discounted vs standard action by a ratio of 5:1. Also, this news comes out usually at 8 or 9 AM. In my subjective opinion, news spikes last about 30 minutes at most 1 hour. If that were the case 9 AM would be the all time volume and volatility high. Now it is the highest volatility bar, but 10 and 11 AM are really within a hairs breadth.
So I would venture a guess on a CHI-squared test they would come up being from the same distribution, and be statistically similar. The max volume for the day is clearly at 10AM well after the 8 AM news breaks, 9 AM news breaks should have calmed down. So why is that, I can only venture a guess but its by no means conclusive. I think several market factors are in play, the news based strategies are closing out, people who wanted to avoid the news spike are starting to reposition as it slows down, the close of london/ new york cross over, and probably more.
Does anyone have the image in post #57? Unfortuantely, it was deleted on the image hoster.