Senators at a Commerce Committee panel hearing aired concerns Wednesday about rapidly growing prediction markets, appearing largely unswayed by industry arguments that they are not a form of betting subject to state regulation.

Members of the committee’s Consumer Protection, Technology and Data Privacy Subcommittee were in agreement at a hearing that sports “event contracts” on prediction markets bear a strong resemblance to traditional sports betting. They also shared worries about all forms of betting affecting the integrity of sports.

The subcommittee heard from representatives of the sports betting and prediction market industries, as well as stakeholders focused on sports integrity, gambling regulation and gambling addiction.

Subcommittee Chair Marsha Blackburn, R-Tenn., expressed her concern about betting’s impact on the integrity of sports, as well as potential additional risks presented by prediction markets.

“While prediction markets represent financial innovation across many sectors, there are real concerns that they function much like traditional sports betting without the enforcement of state regulators and attorneys general,” Blackburn said.