Who is it ? Whoever it is they are pretty determined to dispose of what seems to be quite a large holding. Frustrating that it is not possible for us to know how many more they are planning to shift.
Are you sure ? The three 1,000,000 trades and the 500,000 look like sells to me - they are at the lowest prices of the day apart from the small trade at 5.085 late afternoon.
I presumed the three 250k trades were sells, as the price was lower than the 5.295 buy which was the first trade of the day. Surprising the price didn't drop.