Finatext Holdings Ltd., a Japanese fintech startup that provides stock trading apps and brokerage infrastructure, slumped on its first day of trading in Tokyo, with shares falling 35% below the issue price.

Having raised nearly ¥20 billion ($175 million) in an offering that was priced at the top of its advertised range, the firm got off to a bad start — the biggest first-day decline in more than two decades for a company that raised at least $150 million. Daiwa Securities Co. and Mitsubishi UFJ Morgan Stanley Securities Co. were the lead managers for the listing.

Finatext is one of six companies listing Wednesday on the Mothers board for startups, in what is a record month of debuts on the Tokyo Stock Exchange. Its offering highlights the growing demand for investing opportunities among a younger generation of Japanese, even as stock ownership still trails far behind markets such as the United States.