“I believe this is something that needs to get built, but I understand we’re not the ideal messenger right now,” Mr. Zuckerberg says in his written testimony. “I know some people wonder whether we can be trusted to build payment services that protect consumers.”

He’ll also try to ease lawmakers’s concerns. “Even though the Libra Association is independent and we don’t control it, I want to be clear: Facebook will not be part of launching the Libra payments system anywhere in the world until U.S. regulators approve,” he plans to say.

But lawmakers have criticized Libra since the project was announced in June, and there’s no reason to think that this hearing will be any different. You can watch the hearing here at 10 a.m. Eastern.

More: Dozens of states have joined New York’s antitrust inquiry into Facebook. The company pledged $1 billion to help ease California’s housing crisis. And Sheryl Sandberg has argued that the company runs political ads, including false ones, for the good of political discourse, not for the money.

Nike and Under Armour change up their C.E.O.s

Two of the world’s biggest sportswear companies have announced new leaders.

• Nike announced that Mark Parker would step down as C.E.O. and become executive chairman. He’ll be succeeded by John Donahoe, a former C.E.O. of eBay who has been on Nike’s board for five years.

• Under Armour said that its founder, Kevin Plank, would also become executive chairman. The C.E.O. role will be taken up by Patrik Frisk, the company’s president and C.O.O.

Mr. Parker’s tenure as C.E.O. at Nike had ups and downs. The company has grown strongly under his watch, particularly in international markets like China. But it also recently had to confront a doping scandal and accusations of gender discrimination.