The big worry imo of course is how many players out there are...

The big worry imo of course is how many players out there are now in it for immediate / ST gains.  We're told time and time again it's a long game, but the makeup of participants has changed pretty dramatically (a lot more investors).  I'm going to have a punt and say recent investors are now increasingly more  'time sensitive' when it comes to expected returns... evidenced by interest only loan stats:

http://www.smh.com.au/business/bank...-interestonly-home-loans-20150819-gj39fj.html

I find some of the figures in that pretty staggering.

Another relevant risk imo is that a decent portion of the market suddenly becomes 'price insensitive' (just get rid of it.. common behaviour in a glut or confidence shock) as well. Hard to know just how much supply will outstrip demand (if at all) but it is still a risk.

I'm not sure how happy some investors (with shorter TFs in mind) will be if growth is less than expected.  They might be acutely less tolerant, and there may be a lot of them...