The SEC set a September roundtable on moving US equity markets to 24-hour trading

The chairman of the Securities and Exchange Commission says the American trading day is about to get longer. Paul S. Atkins said on Thursday that he looked forward to "balancing round-the-clock trading with all-important investor and customer protections," in a statement announcing a public roundtable on the subject.

It is scheduled for September 17.

The session will cover what the commission described as preparations to support overnight trading, operations and resiliency in a 24-hour market, and the opportunities and challenges of expansion. Those are the three headings, and between them they cover the unglamorous part of the problem: who clears a trade at three in the morning, who prices it, and what happens when a system that has always had an overnight window to recover no longer has one.

The roundtable will be held at SEC headquarters at 100 F Street NE in Washington, open to the public and streamed live on the agency's website, with a recording posted afterward. In-person seating may be limited. The agenda and the speaker list are due before the event.

Anyone may file a comment. Submissions go to File Number 4-913, by the commission's internet form, by email, or on paper to the secretary, and the commission cautioned that comments are posted without change and without redacting personal information.