U.S. Securities and Exchange Commission Chairman Gary Gensler sent his strongest signal yet that wild trading in GameStop Corp. could lead to new rules for online brokerages and firms that dominate the business of executing stock orders.

In his most substantive remarks since taking over the Wall Street regulator last month, Gensler said popular trading apps encourage retail investors to buy and sell more frequently—something that can trigger lower returns. The SEC chief also raised concerns that a deluge of customer orders are being routed through a few massive players, which he said threatens “healthy competition.”

A crackdown could hurt Robinhood Markets, whose platform was used by many investors to trade GameStop and other meme stocks, as well as Ken Griffin’s Citadel Securities and Virtu Financial Inc., firms that handled many of the transactions.

“Many of our regulations were largely written before these recent technologies and communication practices became prevalent,” Gensler said in remarks prepared for a House Financial Services Committee hearing on Thursday. “We need to evaluate our rules, and we may find that we need to freshen up our rule set.”

Gensler said he has asked SEC staff to seek public comment on “gamification,” a term describing video game like features that critics have most closely associated with Robinhood. The feedback the regulator receives will inform potential policy changes.

He also said the agency will step up its scrutiny of payment for order flow—the practice in which Citadel Securities and other firms pay brokers for the right to execute customers’ orders. In addition, the SEC plans to review whether it should boost investments funds’ disclosures of short sales and swap positions that are linked to stocks, Gensler said.

His comments were prepared for the third hearing that the House panel is holding on GameStop. Frenzied trading in the video game retailer fueled a Main Street conquering Wall Street narrative in January that became a topic of headlines worldwide. On Capitol Hill, the episode drove concerns that something was broken with the stock market, prompting demands for more regulation and oversight.

Gensler also discussed March’s implosion of Archegos Capital Management, the family office run by Bill Hwang. The firm collapsed after making undisclosed derivatives bets tied to stocks, with its banking counterparties suffering billions of dollars in losses. Gensler said the SEC has authority to extend its disclosure rules to swaps.

“At the core of that story was Archegos’ use of total return swaps based on underlying stocks, and significant exposure that the prime brokers had to the family office,” he said.

This article was provided by Bloomberg News.