Celebrity-Backed Financial Tools for Teens Spur Federal Scrutiny

Online celebrities, startups, and big-name financial institutions are targeting teens as the latest lucrative market for fintech products—and they’ve caught the eye of the Federal Trade Commission.

Companies such as Greenlight based their business model on offering debit cards, budgeting features, or beginner investing tools to minors, while financial institutions including Capital One Financial Corp. and Fidelity Investments expanded services to target younger users. Investors have also thrown hundreds of millions of dollars in the last decade into deals with financial technology startups that cater specifically to teens.

Jimmy Donaldson—better known as MrBeast to 470 million Youtube followers—and Beast Industries …