I think someone is using an algorithm to buy shares without...

I think someone is using an algorithm to buy shares without moving the price too much.
There are a few reasons why someone might want to do this. for example they might want to accumulate a large position without causing the stock without alerting other investors, or they might be trying to build a position without casing the stock price to rise too quickly. Its also possible that the buying is coming from multiple sources, such as retail investors and other institutional investors.
However, the fact that the buying is happening at regular intervals at small amounts suggests that it could be an algorithm trade.