As I know NADEX is the only regulated broker in USA but it looks much more difficult to trade binary options. Traders also should pay commission fees and capital gains tax which reduce net profit. On the other side Nadex gives a much better edge because trders dont play against the broker as they are playing against the market.
How Nadex works?
Each Contract is worth $100 when it expires is ITM, and 0 if it expires OTM. What is different is that traders can buy contracts that are already ITM for a higher price, or buy contracts that are OTM for a smaller price. When the contract settles (by expiry or take-profit/stop-loss) traders are given the difference.
For example you buy a contract for $20 and expires ITM - your profit will be $80.
A Contract that worth $50 is with strike price that is equal to the market value at the moment of purchasing.
If you buy a contract for $60 and its value increase to $70 you can sell it and make $10 gain. That means you can just buy/sell contracts and settle whenever you want before expiry.
How EU brokers work?
You invest $100 in Call or Put option for a fixed expiry time and fixed payout 70-85%. If you finish in the money at expiry your net profit is $70-85.
It is very simple and easy to trade at EU broker but the problem is you are playing against the broker and the payout is less than 100%.
So which one to choose?