Technical explanation of how a "tree shake" occurs

Hi all,

Given the absolute pounding the share price got today there have been some people asserting that "bots" and "instos" have been "tree shaking" and triggering stop losses. I am new to the game so am looking to increase my level of technical understanding around how this process actually works. Often posters will reference this as a fact, yet never explain how the process works.

Often posters will assert that "instos" are trying to accumulate a particularly stock at lower prices and hence driving the price down. However, I can't wrap my head around how this would be possible without them actually selling the share that they actually want to accumulate, hence shooting themselves in the foot -i.e. not accumulating at all?

Can someone provide a link to a video or an explanation that gives a detailed analysis about how what is actually occurring in this process?

I know i must be missing something pretty basic here, but i am keen to learn so i can get a better understanding of the process.

Thanks,

Econ