Pros will work off a average price, so materially, the price...

Pros will work off a average price, so materially, the price they buy or sell isn't a concern to them, its about the profit average.

I think you will find sellers were waiting for a better announcement and when that was not delivered, they did not see a reason to hold longer and most would have still left with a small margin or a tax loss for next month, so while they may have been able to get out at a few pips higher then yesterday 0.029 two weeks ago, most may have been hanging on for better news and rather then falling in love with a stock, they sold out, which is in hind sight the correct thing, as they can now buy back in cheaper or wait and see approach.

Stocks tend to fall hardest when there is so much hype about upcoming announcement and when the delivered, the market is very disappointed with the outcome unfortunately.