As market participants, we are sensitive to changing inter-market relationships. This Great Graphic, from Bloomberg shows the correlation between stocks and bonds. In particular, it depicts the 60-day rolling correlation over the past year of the change in the US 10-year yield and the change in the S&P 500.
As recently as the beginning of Q3, the correlation was above 0.70. It remained above 0.60 until the end of August. The correlation is now inverse (-0.15) for the first time since the April-June 2015 period.
The inverse correlation is not statistically significant. The point is that the previous relationship has broken down. This is a warning sign to investors of a potential shift in the investment landscape. There have only been three periods since the beginning of 2009 that the correlation between the change of the S&P 500 and the change in the 10-year yield has been inverse: today's, the two-month period last year and a six-month period when it bounced in and out of inversion in the second half of 2013.