S and P versus euro usd correlation

[oildaytrader]

Why and how does the correlation breakown?

http://www.thegeekknows.com/2010/03/correlation-report-eurusd-s-500-mar-10.html

http://www.thegeekknows.com/2010/01/correlation-report-eurusd-s-500-oct-dec.html

http://www.askpips.com/technical-analysis/question/is-there-a-correlation-with-eur-usd-and-s-p-500

 

[Martinghoul]

There's a multi-collinearity problem here that makes the correlation specious...