To understand $USD and SPX performances, it is worthwhile to note that we are in different geopolitical environment and at a critical, major breakout juncture, SPX 1550, with inverse relationship between SPX price performance and $USD performance since 2003 and especially since 2006 as shown on the LT $USD and SPX comparative chart.
The weak performance since 2003 seems to be relating to the article which I posted noting that Iran has switched to the euro from Spring 2003.
Note that the article is written by "Independent Researcher" which could be unbiased if the writing is revealing facts. I have not verified his writing, however, based on other readings which I did in the past and based on the $USD performance, the writing seems to contain facts with source links.
In summary, SPX and $USD are showing inverse relationship at the moment and are trading at critical break points which are highly worthwhile to pay attention to.
There are differences between a house built on a rock and on a quick sand, so good to know the foundation.