The Trade Desk (NASDAQ:TTD) shares sank 38% Friday after the company’s Q3 guidance sparked concerns over slowing growth and CEO Jeff Green warned that tariff uncertainty was affecting major advertisers.

For Q2, the company reported adjusted earnings of $0.41 per share, topping estimates by $0.01. Revenue rose to $694 million, above the $685.5 million forecast.

The company projected at least $717 million in Q3 revenue, slightly above the $716.2 million consensus.

The Trade Desk also announced a leadership change, naming board member Alex Kayyal as chief financial officer effective August 21. Kayyal has previously held senior roles at Salesforce and Lightspeed Venture Partners.