I’ll give you an interesting chart:
When economy is good, this ratio trends lower: when rates go up (down), dollar goes up (down), too. When foreign investors are not happy about our economy, they will sell dollars even when rates are high.
I see some sort of trendline from lows of Jul/05 to the highs of May/06, when stock market was making a major dip. Now, when Dow Jones is around all-time high , the index is at 6 months high, i.e. foreign investors are not bringing as much money as they used to. Most likely it’s a result of credit tightening after “subprime” fiasco.