Taking a bigger-picture view, you can see that the dashed red line represented 13-year support for the RUT/SPY. The ratio touched this line on 6 occasions only to bounce higher each time. That changed, however, just a couple months ago. As noted in the blue text box, the ratio recently broke 13-year support, back-tested the line, and is now falling once again.
The last time long-term support was violated back in 2007, the S&P plunged only months later. Are we set up for a repeat performance now that an even longer-term support line has been violated?