这个strategy so far so good:http://bbs.wenxuecity.com/finance/2614330.html
The followings are two longterm US$/SPX charts, 你看下找找感觉:
1) $USD:$SPX - Weekly Long Term
http://stockcharts.com/c-sc/sc?s=$USD:$SPX&p=W&yr=20&mn=0&dy=0&i=p81055765517&a=239857886&r=937
2) $USD - Monthly Long Term Prognosis
http://stockcharts.com/c-sc/sc?s=$USD&p=M&yr=20&mn=0&dy=0&i=p63929609666&a=189900700&r=179