Quote from parisd:
It is not a perfect system and not a risk free system, it is just an idea send around and may be need to be investigated further, seems that someone somewhere made it to work.
You make your 2 pairs to be correlated as close as posible to 100% (there are website giving correlations) then You should immediately have limit buy or limit sell that come automaticaly to readjust the correlation it it deviate from neutral and it will.
The idea and the difficulty is to calculate with a good accurancy at what level to place automatic buy or sell, may be multiple buys and sells at different levels in order to maintain the neutrality of the correlation during normal fluctuations of currencies pairs, of course not during black swan event. if we succeed during normal trading range, then the account value should remain almost constant but differential of interest will be added according to number of lots you have and you may have many lots open with very little risk as you are in a neutral position.
Black swan event are not frequent if you use major currencies like $US, £ and Eur or Fswiss and tell me who will not be affected during a Black swan event unless by chance he is on the right side at that time.