Trading on Nadex starts at 6PM ET of the previous day and runs overnight until 5PM ET on Monday through Thursday and until 4:15PM ET on Friday. Nadex pauses trading from 5-6PM ET for exchange maintenance.
Individual markets have their own trading hours which may be slightly different from the exchange open hours. You can find them on the contract specifications page for each asset class:
Why traders need to know a market’s trading hours
Trading hours on Nadex encompass both what other exchanges call regular trading hours or the trading session—traditionally the time between the opening bell and the close—as well as after-hours trading.
Nadex traders want to know the exact trading hours for each contract because all Nadex products are options, which have expiration times. As the contract approaches expiration, it loses extrinsic (time) value.
With a 20-minute, 5-minute, or 2-hour binary option, for example, you should know the exact start and expiration time of the contract in order to take full advantage of the time available.
In every trade, you can choose your initial cost and maximum possible profit up front. You know your maximum risk exposure. You can (and should) also know and choose the time frame.
Check the trading hours before choosing a contract duration
For example, if you believed the EUR/USD forex pair was in an uptrend, but the market move you want to trade could take a few days to happen, you’re not going to be trading the contracts with 2 hour durations. More likely you would choose a weekly binary contract and enter the trade on Sunday evening or Monday.
On the other hand, if you are trading a move you expect to happen in the next hour, you would probably not choose a weekly binary because it would not make sense to pay for time that you are not going to use.