Excellent Post, Dark trader. You very well spotted what what have been harming equity brokers and dealers for a while now : an increasing lack of interest for equities and a switch to bonds. It's reminiscent of what happened during the crisis in early 2009 : to understand the rationale of such a transfer, one needs to imagine to be in an asset managers' shoes : end of 2008, after Lehman's collapse, your portfolio was deeply hurt by the equity markets, you were scared for your job, your management was equity averse and then you had corporate bonds, providing a high yield for a default risk that could be considered as limited.. So going to bonds was a no brainer and that's why the fixed income assets and particularly corporate bonds did their best year in 2009 in terms of volumes and flows (meaning profits for dealers and brokers).What we highligthed here could be a part of the very same process and that could be the very beginning of your Bubble.
I agree with you, global macro parameters and Central Banks actions will be key on how this will play out. I'd say the equity/bonds allocation depends to a large extent on inflation prospects : stocks are long inflation, fixed income assets including bonds are short of it.
Now the only thing I'm not sure about, is the link between the volumes and price direction which is to me not that straightforward