Before the U.S. AAA debt rating cut, the break in the S&P in 2011 ended up falling hard. In 2011 Euro followed the S&P shortly after.
I am a little concerned that both the current S&P and EUR/USD setup which is similar to the 2011 top. Notice how the price action moved below the line (purple), backtested the bottom of the line and then broke down. Its an interesting similarity.
One thing that was interesting with the S&P and EUR/USD break was that there were three different slopes. The major fall happened when it broke the long trendline with a lower slope. The current trendline is on a very similar slope to the main purple trendline of 2011.