U.S. Securities and Exchange Commission (SEC) Chairman Jay Clayton will leave his role at the end of this year.

Announced in a press release Monday, Clayton led the U.S. regulator for 3.5 years and through what the SEC called a "period of historic productivity and unprecedented challenges.

"Thanks to the hard work of the diverse and inclusive SEC team, we have improved investor protections, promoted capital formation for small and larger businesses, and enabled our markets to function more transparently and efficiently,” Clayton said in the announcement. 

Under his leadership, the regulator has consistently rejected proposals for a bitcoin exchange-traded fund (ETF) on grounds of concerns about fraud and market manipulation. However, recently Clayton softened his stance by expressing openness to the idea of a tokenized ETF.

Regarding his role in the digital assets space, he told a Senate committee in 2019 that the SEC has taken "a measured, yet proactive regulatory approach that both fosters innovation and capital formation while protecting our investors and our markets."

The SEC has taken numerous actions against crypto initial coin offering (ICO) projects under his watch, though he has said token issuances can be an effective way to raise funds as long as the rules are followed.

Clayton's decision to step down comes ahead of an impending change of presidential administration in the White House.

Also read: Mapping the Future of the SEC (There’s a Nonzero Chance Hester Peirce Takes Over)

While President-elect Joe Biden hasn't yet suggested a name for the SEC chairman role, his transition team members include Gary Gensler, former chairman of the Commodity Futures Trading Commission, suggesting the possibility of a stricter regulatory oversight under Biden's leadership.

At one point during the summer there was talk Clayton would become the next U.S. Attorney for the Southern District of New York after he was nominated by President Donald Trump for the role. Ultimately, that did not happen.