expression, godan verb (-su)
build a fortune; make a fortune
Used for accumulating substantial wealth, often through business or investment.
彼は若くして財を成した。
He built a fortune at a young age.
Similar meaning, but 富を築く emphasizes building wealth over time, while 財を成す focuses on the achievement of a fortune.
Compound of 財 (wealth) + を (object marker) + 成す (to accomplish). The expression literally means 'to accomplish wealth'.