Research, page-984

Hey Reddevil67, these little trades are done by Bots/ Algorithmic trading programs implemented by market makers to maintain liquidity and maximize profits by systematic trading at the exclusion of human emotions. While these small, sometimes trifling trades can seem perplexing to us, even ridiculous and vexing at times, taken as a whole they can generate substantial profits for the market maker when executed in numerous stocks concurrently.

While they do generate frustration, they also facilitate investors allowing us to accumulate larger positions at discounted rates.

I'm sure there are smarter people than I who can explain it better.
Incidently, I picked up another parcel today too.