The US Securities and Exchange Commission’s top enforcement attorney says that Wall Street’s main regulator is very concerned about digital engagement practices that brokerages may use to encourage more buying and selling of stocks.

While SEC Enforcement Director Gurbir Grewal refused to discuss any investigations, his comments during a House subcommittee hearing on Tuesday are the latest signal from the regulator that a crackdown is coming for practices that critics refer to as the gamification of investing. Last month, the SEC said it planned to propose new rules this year.

“Gamification is a huge concern,” Grewal told lawmakers on the House Financial Services Committee’s Subcommittee on Investor Protection, Entrepreneurship and Capital Markets. ”I’m concerned when gamification crosses the line into a recommendation,” he added.

He added that the SEC could take action if firms using digital nudges on customers don’t comply with rules requiring them to act in clients’ best interest when making financial recommendations.

The SEC said last August that it was concerned that game-like features are putting investors at risk by encouraging excessive trading. Under SEC rules, if a firm is offering investment advice or recommending securities it can face conduct standards that require putting clients’ interests first. 

This article was provided by Bloomberg News.