It's not there just to allow accumulation. It's so obvious that the trader using TD is shuffling shares around and forcing people to sell lower. But the real value of that wall is when those same traders take it out themselves.
They buy their own wall down, resulting in much higher than average volume spike, wihich technical traders look for and many alerts trigger on. Once the wall goes down, the price shoots up, confirming the volume preceding price rule, leading to more gains, which benefits TD/Anon as the value of the shares they accumulated goes up higher than if the wall was never there in the first place.
PTK has been a low volume stock for so long, any increase in volume is quickly noticed. Hence the big walls.
