So, that initial downwards spike at -400ms that immediately kicks back up to the halfway point?
Those can only possibly be pre-programmed strategies. From the big boys. 'Cos you can't stack 'em exchange side last I checked, if they're price dependent. Which means they have a gloriously low-latency-close-to-the-exchange-link.
Which means this news was leaked well before the event.
Sure you can "stack" them. If you place a sell order larger than any of the buy orders on the exchange, then what you will see is a "stack" of executed orders beginning with the highest-priced buy order and working down to cheaper ones.
In any case, the bounce back looks to happen over ~100 ms or so, which is plenty of time for anyone's strategy to catch up. I don't see how you can conclude there is some big player who knew "well before the event."
Those can only possibly be pre-programmed strategies. From the big boys. 'Cos you can't stack 'em exchange side last I checked, if they're price dependent. Which means they have a gloriously low-latency-close-to-the-exchange-link.
Which means this news was leaked well before the event.