Quote from USAtrader:
Why go the extra step when they already handle dollars (actual, swaps, and other related transactions), why not just do that.
The negative correlation between falling USD (at least as it relates to the EUR) and rising SP is NOT long over. I'm not normally active in currencies, so I can't speak to things prior to the month of May and June this year. So I'm just speaking regarding flash crash through today. During that period there has been an extremely close intraday relationship between the EUR.USD and US equities. If you watch the movement day to day and during the overnight sessions you can see programs every day that are just buying and selling spooz along with the movement in the EUR.USD.
Edit: I would just add that it seems that intraday a lot of this corelation seems to often have a slight advance move. I.e., one will sometimes lead the other then quickly play catch up.