can you give some sources on these please? or what do you mean? capital efficient as in kelly, diversifying accross markets, diversifying strategies etc.?
Cross hedging is just using related futures to trade long and short at the same time.
You can buy one NQ and sell two ES. Then wait for market to move up or down. When it does close the profitable contracts and let the other contract roll down so that you made money on both directions. Easy way to make more profits.
Another example would be like buy FDAX and sell Eurostoxx 50.
This is also called spreading indexes or spread trading.
Capital efficient means that you can use more leverage with less margin. Good traders know how to use leverage to take advantage of market opportunity.
If you have $100,000 and you want to make big (index) trades you can take advantage of SPAN margin using the CME exchange rules.
If you just try to trade the biggest ES position you can, you can trade something like 18 lot with this much money (at conservative broker).
But, SPAN margin gives margin offset so calculates margin on
all positions. If you have a position say
Short 15 NQ, this is $2,367,885 which is super leverage.
But, keeping that position on you could execute a 26 lot ES trade long (this is almost $4,000,000) because the first 12 lots will just reduce your margin.
Think about it, with these two trades I am using something like $6,000,000
This is an extreme example but you see how you can trade bigger if you do this kind of thing.
These are professional techniques.