noun
promising stock; stock with potential
Used in finance and investing contexts for a stock expected to rise in value.
アナリストはその企業を有望株と評価した。
The analyst rated that company as a promising stock.
noun
promising person; person with good prospects
Figurative extension of the stock sense; refers to a person expected to succeed, often in business, sports, or entertainment.
彼は若手の中でも特に有望株だ。
He is a particularly promising person among the younger members.
株 means 'stock' or 'share'; 有望株 combines it with 有望 to create the specific compound.
Compound of 有望 (promising) and 株 (stock, share). The figurative use for a person is a natural extension of the financial metaphor.