Nasdaq Sets Test Windows for Dec. 6 Launch of 23-Hour Trading

Nasdaq told market participants it will offer three ways to test overnight trading before nearly continuous 23-hour, five-day trading starts on its stock market on December 6, 2026.

In Equity Trader Alert #2026-56, issued September 28, 2026, the exchange said the tests prepare firms for the new overnight session, which it had announced earlier (see prior coverage).

The first window is the Nasdaq Test Facility, open since September 1, 2026. Participants need Night order entry and market data ports for the test facility. Both production and test symbols trade Sunday to Thursday from 9 p.m. until 4 a.m. the next day.

The second is a set of weekend user acceptance tests on October 2, October 16, October 30, November 6, November 20, and December 4, 2026. Participants need production Night order entry and data ports. Production and test symbols trade from 11 p.m. Friday until noon Saturday.

The third is a pre-production period beginning November 1, 2026. It uses production Night order entry and market data ports, and only test symbols trade. Sessions run Sunday to Thursday from 9 p.m. until 4 a.m. the next day, and Nasdaq said it will broadcast market data for the test symbols.

Nasdaq pointed participants to its Global Trading Hours Hub for more information.