Prediction markets are facing renewed scrutiny from federal lawmakers after wagers about the fate of Iranian leader Ayatollah Ali Khamenei, who was killed in the Saturday bombardment of Iran.

“It’s insane this is legal,” said Sen. Chris Murphy, D-Conn., in a post to X, referring to another post highlighting people who had made money on the invasion. “People around Trump are profiting off war and death. I’m introducing legislation ASAP to ban this.”

CNBC has reached out to Murphy’s office for more details on his proposal.

It comes as a new trade group led by President Donald Trump’s former acting Chief of Staff Mick Mulvaney, Gambling Is Not Investing, launched to push tighter guardrails on prediction markets.

Other lawmakers, too, have expressed concern about prediction markets after the invasion. Rep. Mike Levin, D-Calif., said on X that ”[p]rediction markets cannot be a vehicle for profiting off advance knowledge of military action.”