“Is this perhaps more than an ordinary correction?” Mr. Shelby asked.

Jay Clayton, the chairman of the S.E.C. said that he could not tell what had caused the big declines, but he said that the market infrastructure had held up well under the strain of heavy trading.

“As I sit here today, there’s nothing that came out of this that concerns me,” Mr. Clayton said.

Christopher Giancarlo, the chairman of the C.F.T.C. said that his staff had a late night on Monday checking in with all the exchanges, and had not heard anything that concerned them.

“The system worked as it was designed to do,” he said.

— Nathaniel Popper

Is algorithmic trading to blame for Monday’s plunge?

Following a House Financial Services Committee hearing, Steven Mnuchin, the Treasury secretary, said that he has been in touch with market participants this week and that they are reacting in an orderly fashion and that there are no liquidity problems. He said it was possible that algorithmic trading was partially responsible for the recent volatility in the stock market.

“I have heard from others that it has played a role, as there’s more programmed trading, this tends to have volatility in both directions,” he said.

Despite that volatility, it does not appear that the Trump administration is ready to give up on the stock market as a measure of its success.

“We’ve always been looking at the long-term impact of the stock market, it’s still up over 30 percent since the election and we continue to think American is a great place to do business,” Mr. Mnuchin said. “We couldn’t be happier with companies’ response with more and more investments in the U.S.”

— Alan Rappeport



Steven Mnuchin isn’t concerned about the stock market turbulence

Asked about the roiled stock market at a House Financial Services Committee hearing on Tuesday, Steven Mnuchin, the Treasury secretary, said that the Trump administration was not concerned and that it remains focused on the long-term trajectory of the economy.