• 株主かぶぬし — shareholder
• 株式かぶしき — stock (of a company)
• 親株おやかぶ — parent stock / original plant
• 株価かぶか — stock price
• 古株ふるかぶ — old-timer / veteran

株 combines the tree radical 木 with 朱 (シュ, “vermilion”). Originally referring to a stump or root, it later symbolized shares or authority that branch out from a central source. Today it’s essential in business contexts (株式, 株主) while still keeping its older meaning of tree stumps or roots.

彼かれは 株かぶを 買かいました。
He bought some stock.

株主かぶぬしは 会社かいしゃの方針ほうしんに 影響えいきょうを与あたえる。
Shareholders influence the direction of a company.