Where does “pienomistaja” come from?

pienomistaja (Finnish) comes from Finnish omistaja, from Finnish jä, from Proto-Finno-Ugric *ja, from Proto-Germanic jahw, from Proto-Germanic -hw, from Proto-Germanic -hwe, from Proto-Indo-European -kʷe — and; Forms distributives from interrogatives.

pienomistaja (Finnish): small proprietor; someone who only owns a small part of something, e.g. of shares (i.e. small shareholder)