It is an interesting question and the easy and smart alack answer would be...
Whenever it WINS.
But honestly its really a matter that has a lot of components to it.
I think the best time to trade is when you are available. I have traded for a couple of decades I have seen a lot and done a lot of different things. One of them is waking up in the middle of the night to trade. Now maybe you have done that yourself and maybe it works for you. But for me it isn't worth it. We have 24 hours in the day, sure the forex markets are more active at certain times. But at the end of the day, if your end lifestyle doesn't work for you, the system/signals/method won't work for you long term.
So first I would say decide WHEN you can trade.
If its during VERY active times you can determine the best course of action for trading during those times. For example if you can only trade during the US open or jobs reports that is VERY different trading then trading at 4pm eastern when things are QUITE SLOW.
You can't cram one method into a time frame that doesn't work for that method. So rather then find a method that works for you I prefer to find a TIME that works for you.
The issue with finding the method/signal/system first, is their are a LOT of ways to make money/and lose it in the binary option forex market. So what ends up happening is you find a method that works but it is HORRIBLE for your lifestyle due to middle of the night etc.. What ends up happening is you go thru a losing streak (everyone does) and you get discouraged and end up skipping winning trades (you oversleep) and take the losing ones.
Then after you decide that method and time frame isn't right for you. You go and find a NEW method/system/signal and do the process all over again.
When you START with the TIME that works for YOU. You end up eliminating a lot of noise and methods that just aren't right for you. Their is NOT a one size fits all in trading. Warren Buffet has does extremely well in the markets over many many decades but that DOESN'T mean that is the ONLY way to make money in the markets. Anyone that teaches a system/signal/method that works the same for everyone you should RUN far away from.
My trading time frame, money management, method, signals, systems etc.. just because they work for me doesn't mean they work for YOU.
So starting with when your available to trade just makes things a LOT more simple. (Which is the kind of stuff I LOVE.)
So MANY articles have been written about the best times to trade based on market movements etc.. You can do a google search and find a handful with different charts etc.. But again that goes to the fact when the markets are active which MAY NOT be the best way to trade.
Remember Binary Option Forex is a bit different than trading the straight forex market. With binary option forex I can make money when the market doesn't move much at all. And trading at Nadex I can make money on In the Money contracts. (Meaning: I could buy a contract for $75 on the Eur/usd 1.0650 even though the market is at 1.0660. So even if I was WRONG but not by a lot I make money)
You can make money via Out of the Money (OTM) trading and getting paid 300%+ return on your money.
You can make money via In the Money (ITM) trading and getting paid 25-35% return on your money.
You can make money via At the Money (ATM) trading and getting paid 70-100% return on your money.
But an ITM method maybe HORRIBLE idea during a jobs report or FOMC Announcement. But it could be a GREAT idea when the markets are less active.
Their is NO best time to trade the forex market for everyone.
However their is a best time to trade forex for YOU. And ONLY you can decide when that is.
Personally I like daylight hours eastern time to trade.
I have a signal service that gives signals at 6pm, 8.45am, 9.05am, 11am Eastern. You can find it at LazyBinaryOptionSignals.com
But I also have some systems that I have traded for years. They tend to trade between the hours of 10am-3.30pm eastern depending on the systems. (Those systems are also part of the LazyBinaryOptionSignals.com package.
Another aspect of time that I like to keep in mind is I like to place the trade and WALK AWAY. I have ZERO interest in watching the computer all day long. Even during the hours I listed above I am NOT watching the charts all day. My signals and systems are ALL time based. By that I mean I know EXACTLY when I need to be available during the day.
For example my Eur/usd Lunch trade (which you can get for FREE) ONLY trades at 12pm noon eastern time. That is the ONLY time I need to check that trade. It doesn't happen at 12.05pm it ONLY happens at 12 noon eastern. So if the system doesn't have the right setup it just isn't a trade for that day.
The other problem I find with watching the charts all day. Is basically you have just given yourself a high stress job. The point of trading to me is making money so I can do other things. Don't get me wrong I enjoy trading very much for LOTS of reasons. But I trade so I can live my life. Trading isn't all I want to do with my life.
So find the time that works for YOU and that is the Best time to trade the Binary Option Forex market.
P.S Be sure to get your FREE copy of the Eur/usd Lunch time trade.