Regulatory costs are a major hindrance to companies going public, former Securities and Exchange Commissioner Paul Atkins said today.

Sarbanes–Oxley Act rules and other regulations are contributing to a downward trend in initial public offerings, the Republican said at an Insured Retirement Institute conference in Washington. The availability of private money and the prospect of class-action lawsuits also are factors, he said.

“We do all of us know that [chief financial officers], investors, and others all take into account the cost of doing business and regulations,” said Atkins, chief executive of Patomak Global Partners LLC. He led President Donald Trump’s transition team focused on financial services regulation.

Jay Clayton, who became SEC chairman in May, has said he will work to reduce IPO hurdles, but has yet to provide a detailed plan.