FRA is a death trap(traders are at the mercy of unions and French passion)
only DAX, US100 and EUR 50 offer the most opportunity.
However, you need to know the underlying forces behind each index. At hedge funds around the world traders only trade 1 or 2 at the max. Traders are educated in what they are trading… They can tell you what is the biggest component in their index!
For example, the DAX is made up of car manufacturers with the majority of their revenue from China… Mercedes has plants in Georgia(US) which ship to China, so Chinese tariffs on US cars will hurt Mercedes/Daimler which could bring down the DAX.
To trade the DAX you will also need a grounding in German politics…
I didn’t mean to go on but I would say its best to be narrow and focussed …Understand what moves an index and build up screen time watching it move through the day.
Where are you based?