There are a couple reasons that I can think of.
Post# of 82672
1. They could be speculating that a stock will inevitably take off. And just like anybody else they would want to add to their position for as little as possible.
2. They could make quick money off of fluctuations. If the price starts to elevate a little, but has no real catalyst at the moment, then they could sell from their current position. And use the rest of their position to drive the price to to recover sold shares at a cheaper price.
Also see these links.
https://www.investopedia.com/articles/financi...tricks.asp
https://www.advfn.com/Help/a-background-to-th...ma-71.html