Wash and rinse is the bitch.
That's what they do.
They create volatility in a position to a degree that it's untenable for anyone who uses stops of any kind to establish a long term position.
By they time they start accumulating for good (they've identified these equities months, maybe even many, many months ahead of times, and have been ramping and plunging it repeatedly), pikers like me already view the equity with disdain as being far too volatile to ever touch again.
I know this is what I've experienced many times.